This way of reasoning has its merits. But on the flip side:
- If Hamilton gets Line B LRT this time, it will be in very good position to ask for Line A LRT / BRT at the next round of transit expansion, or the next next round. Maybe 4-5 years from now, maybe a bit later.
- If they build Line B and A BRTs instead, then all the stars will need to allign really well to get either of them upgraded to LRT. As long as the ridership is within the BRT margins, noone will bother upgrading. So, several transit expansion cycles will be skipped. Then if the ridership demands LRT eventually, the upgrade will have to wait until the fund holders feel like giving something to transit. And even then, the construction in the already popular corridor will be somewhat disruptive.
Furthermore, density may be growing faster along LRT than along BRT on the same route, due to the permanence factor. Btw I am a bit skeptical about that factor playing a big role in 416; if they want permanence, they will just build near subway stations, plenty of slots are still available. But in Hamilton, it's another matter: LRT will be the best transit line in town, going straight through the centre. Businesses will have a reason to locate near LRT, knowing it isn't going away, and then the residential construction will follow.
Generally, when a municipality chooses between two transit options, both options being somewhat reasonable, but one is cheaper and the other is more future-proof: a smart municipality should always go for the second option, if the fund holders don't object.