So the movie has made this "alternate timeline", does they will never make a new TNG era trek for tv because it would be too confusing?
A large part of the reason for setting TNG in a different "era" than TOS was to reinvent Trek without having to account in detail (not for a number of years in any event) about why it was different from the original series and the movies. In many respects TNG initially ignored the existence of the movies beyond ST:TMP other than where models etc. needed to be recycled for practical reasons.
That "firewall" would make another TNG-era series pretty easy to do while ignoring the differences between nuTrek and oldTrek.
In any event, the producers of a new TNG-era series would probably want to reinvent the 24th century quite a bit anyway. In that case, the Abrams reboot actually would make that simpler to justify.