Here's the full game subs section without the important parts you removed. In addition to this 1 year of "exclusive negotiation window", they have 120 days to negotiate exclusively with Sony. If they don't have an agreement, then they can negotiate with other platform (like MS) to include it in a non-Sony game sub. Then Sony has at least 60 days more to negotiate/match that offer. If after these 60 days they don't get an agreement with Sony then they can sign with the other one (MS).
So if Sony tells them to negotiate a this a few days before the year ends, means that during 1 year and 5 months (plus the time they spend to negotiate with MS in the middle) it won't be on GP.
This means that if Sony wants, can keep the game for up to almost a year and a half outside GP and that would be without signing it for PS+. Obviously, if they sign it for PS+ they may make a separate deal, where they could say that during a certain period of time more it won't be in rival game subs.