United Airlines has been adding capacity on several routes to Canada, obviously in partnership with Air Canada. I don't have past frequencies to confirm if UA is adding or replacing AC service, but my thought is that it is additional. Ie. they added YYC-IAD, YYC-LAX, YUL and YYZ to SFO. And all the mainline up gauges. UA used to be so reliant on RJs for so many Canadian routes, but they've become much more mainline lately (both YYC and YVR are entirely UA mainline this summer, with daily+ to SFO, LAX, DEN, IAH, ORD, EWR, and WAS from each) AC has been pretty static I think, they haven't cut back really (other than from YYC, where they pulled out of SFO, LAX, DEN, IAH, and ORD and handed UA everything, the only route they kept was EWR). But they also haven't added noticeably. So UA is doing the heavy lifting for both airlines on several UA hub routes now, freeing up AC to operate increases to cities that aren't UA strongholds (ie. Austin, Miami/Florida in general, Phoenix, etc.). Really makes sense, it's the main point of a joint venture, that flexibility.
I never realized our bilateral with Turkey was so restrictive. UAE always seemed to get the attention in terms of miniscule bilateral allowances, and the frustration by carriers like EK with such low flight frequency. EK is a behemoth on so many routes to places that don't have tight restrictions like Canada, so as much as I don't like government overreach, keeping a tight leash on flights was probably a wise move by Canada, even though it isn't an inviting quality for many airlines. But then there's TK, the silent monster that wasn't as flashy as EK for advertising, it didn't have the reputation of a power player in the international market the way EK had, and it wasn't world renowned for crazy in flight offerings (EK was all about the A380s and big new planes, including the super luxurious first class offerings like private suites). From what I see, TK still only has economy and business class on all flights, that's very basic, not even premium economy. And yet here we are, and TK and IST airport are eclipsing EK in many respects, here's just a snippet of the Wikipedia article:
As of 2022,[needs update] it operates scheduled services to 340 destinations in Europe, Asia, Oceania, Africa, and the Americas,[8] making it the largest mainline carrier in the world by number of passenger destinations.[9][10][11] The airline serves more destinations non-stop from a single airport than any other airline in the world[12] and flies to 126 countries, more than any other airline.
They really came right for DXB and EK, and it wasn't splashed in the headlines or discussed even amongst AV geeks the way EK was. EK was the giant who could wipe out local and foreign competition, and build connections to DXB (possibly also being a deterrent to other airlines adding capacity to cities where DXB intimidates competitors). Yet all along, TK was building a massive global network through a single connecting hub the way DXB was, but never got any of the hate. They are doing exactly what DXB did (without the flash and opulence factor), but even more well positioned. So the fact that Canada has a tight bilateral with Turkey shouldn't be surprising, I just never knew about it. It certainly does explain why TK frequencies are so low on routes that could certainly absorb much more (3x weekly to YVR and YUL, and sub daily to YYZ?! I definitely should have known these low frequencies were due to government restrictions and not demand).
It is such a bizarre relationship Canada (and especially Air Canada) has with these ME airlines... TK is a full member of Star Alliance and has been for a long time, so they are supposed to be teammates with AC. But I don't see that at all. Yes there's some minor codesharing, but it's not that extensive. And then there's the bipolar saga with AC and EK. Basically AC saw EK as its adversary, plain and simple. Everyone knows AC was the big supporter of restrictions on EK, to protect their own routes to Europe, India, and their close relationship with LH from FRA and MUC. Years pass, you don't hear much about the issue anymore, and then all of a sudden AC announces a partnership with EK? Like a formal partnership, with a media blitz promoting their new cooperation. AC even codeshares with FlyDubai, the other Emirati owned airlines, focusing on regional ME and South Asia! Interestingly, at this same time United signed a similar partnership with EK, after previously taking the same position as AC (tight restrictions and defensive tactics to keep EK out). Something happened that made these *Alliance stalwarts pivot to partnership with EK, I am not someone who believes in rubbish like plots or blackmail or bribery being the reasoning for international events, but the AC/UA 180-turn regarding EK and DXB was really surprising. I can't help but notice there's no sign of LH and EK getting into bed together, they don't have any codesharing together. LH was probably a bit ticked off that their two big North American partners (and close ones) did this. Unless AC and UA gave LH advance notice, I have no clue, I have zero read or sense what the nature of their cooperation is and who is more dominant). And then here again we have TK and IST. AC could make IST more of a priority, having some of their own flights there (which are allowed in the bilateral), or even just stronger codesharing and domestic connection cooperation, but it doesn't seem the case. They (AC) don't fly to IST themselves at all, they are seemingly more focused on partnering with a non-alliance, dominant competitor at DXB than with a *Alliance partner airline and their home base?!