Given that even Mozilla (who has significantly less resources than Google) had the ability to create a second web engine and then abandon it, it would be dumb to think that Google doesn’t have at least 2 or 3 teams working on different browsers or engines for no reason.
Unless they’re prohibited from creating another web browser ever again (which would most likely be a bad idea), they can probably come up with a working browser in less than two years
I guess 5 years is not too bad, but the judge would probably never agree to the ban.