This is included in what you write, but it should be noted for emphasis that Bill 101 prevents Anglophone immigrants from receiving (public) education in English. That is, a family that moves from Ontario to Québec can receive English-language education for their children, but not one that moves from the UK to Québec (even after naturalization as citizens).
To the extent legally permissible (Québec has a special exemption from a portion of the constitution's minority-language education section), the province takes a model of education where English-education should only be provided to the existing minority, and immigration must bolster the Francophone majority.
It prevents everyone from getting public school English education in the province unless one parent also went to English high school in Quebec and has a special letter to prove it.
All immigrants are prevented, including those from other provinces, all French Canadians as well (unless they have said letter).
As far as I remember from speaking with coworkers from Quebec, there was a loophole as sending your first born child to a private English school ($10k) fro one year and then transferring it to public English school and after that all siblings can go there as well, but I think this is closed now...
At the same time the majority of the separatists leaders children go private English schools...
> It prevents everyone from getting public school English education in the province unless one parent also went to English high school in Quebec and has a special letter to prove it.
Only one parent, and they only need the right to have gone to English school, in Canada. Yes this may be made more difficult in practice due to some bureaucratic requirement.
To the extent legally permissible (Québec has a special exemption from a portion of the constitution's minority-language education section), the province takes a model of education where English-education should only be provided to the existing minority, and immigration must bolster the Francophone majority.