That's not proven physics, just speculation. There are no answers at this point, especially regarding end of the universe.

Also, infinite universe is not necessarily the same thing as a growing one.

For all we know all we see could be some local quirk of spacetime or whatever that creates a weird projection. I would at least wait for a return data from a probe in nearby star system's before accepting that yes, that's probably how it actually is, at least in our larger neighborhood.