They're not forcing it on anybody any time soon. Until Unity 8 has parity with Unity 7, it's not even going to be considered as the default. Funny thing is, their efforts to avoid the issues with and backlash against the original Unity are the reason Unity 8 has been delayed for so long.

Whatever else you might say about Canonical, at least they're doing the whole 'convergence' thing in a pretty open and responsible manner.