Reliability and capacity are much better places to focus scarce resources.
As for Porter, the seat capacity has much more to do with weight limits out of the island airport in Toronto than anything else. Air Canada flies a
similar set up out of the island.
Some users will make the choice not to ride LRT in Calgary due to perimeter seating, just like some users in Toronto will make the choice not to ride their new streetcars because the seats face backwards, and some are arranged in
quads (egads!).
If people that already had a seat (a minority), now have a seat that is slightly less comfortable, and requires them to look across the car at someone (how is this worse than the Quads and side seating alternative on the old U2s), and are now so uncomfortable they are willing to pay much more for an alternative means of transport, who cares. I just don't see this being a widespread issue, and economics will lead to the spot being filled since we are at capacity for both LRT and parking to the main traffic driver.
A lost rider (or even many) is not a problem as long as in aggregate service is improving on core metrics (reliability, including the reliability of being able to board the first train you encounter).
Now if lets say the system was running close to but not at capacity, and we replaced all the trains with a lower number of trains that could carry more people individually (with less comfort), but cut the total number so total capacity stayed the same that would be an issue (since the problem you guys noted would have a material effect on total system usage). But that isn't what is happening.
Adding capacity costs an incredible amount of money, not trying to wring as much use out of our current infrastructure before we need to do the second phase de-bottlenecking (the 8th Avenue Subway, along with major LRV and staffing increases) would be a waste of scarce public resources.