This feature actually sounds like something that is aligned to Mozilla's mission of an open internet (paraphrasing).

Now, from where this cost is going to be recouped, how seamless the integration will be (in-browser translation is useful but the UX is not good enough), or if their VPN exit points aren't flagged to death as bad IPs; will remain to be seen.

The other thing about this feature, is that it will prove interesting in France and the UK; where it could be seen as a circumvention technique of the currently in place age restriction laws. And at the very least, it will bring those topics back into discussion.