do i think that similar legislation could ever pass in other provinces?
i'm not aware of any movement for it.
i'm going to guess that the calculation at the federal level amongst all of the parties is that, while it may gain passive support with passive voters, it's not worth whipping up the opposition. it's one of those things where you might get 51% of passive voters to passively support it, but that 15% that is going to strongly oppose it is going to cause a havoc, when they do. it's a loud, vocal opposition - and it's not worth the headache, especially given that i don't think that any of the sitting leaders have any particular conviction for it. trudeau is an empty vessel, and to an extent it doesn't really matter what he thinks, as a person.
quebec has a weird spectrum that is at the root of this as a political issue. in provinces like ontario and manitoba that maintain the traditional 3 + 1 or 3 + 2 canadian spectrum (that is liberal, conservative, ndp and a usual fourth, sometimes fifth, party), the same calculation as exists at the federal level is probably dominant, but in the provinces that have less stable spectrums, one could see it coming up as a potential issue.
the province with the highest incidence of non-belief in canada is not ontario or quebec but british columbia. could the bc liberals support something like this? alberta is perhaps too conservative to talk about something like this, but saskatchewan is a more interesting test case. these are places where a secular left could use it as a wedge issue against a pseudo-left party that is embracing tory multiculturalism as a core identity. how many atheist asians in bc would support this?
i think you'd have to see it in a second or third province before the liberals in ontario took it seriously - and i would expect both the ndp and the conservatives to strenuously oppose it, here. it would have to be the liberals, if it were to happen at all.
i couldn't really imagine it gaining traction anywhere in the united states, but america is a much more religious country. canada is more european, in that sense.
i'm not making predictions, i'm just thinking out loud. but, i do have a feeling that it's a policy that we're going to see more of, not less of.