Any kind of structural rebuild of Eglinton LRT is extremely unlikely. That would cost too much, the transit funds can be used elsewhere, and there is no fundamental problem with the current design that can't be solved in a much cheaper way.
If the line can handle the demand, just runs slower than it could in the east - they will do nothing. Just think of Subway Line 1 that has a few slow-order sections; those stretches are a bit annoying, but noone panics.
If the demand exceeds the capacity, they will replace 2-car trains with 3-car trains. The current design allows that, with minimal changes.
If the demand still exceeds the capacity, TTC will try to tweak the bus routes, meanwhile exploring new lines that could take some pressure off Eglinton (OL North, Lawrence, Vic Park).