Something something likely server limitations. If they did not care to come back or find a way to contact you during a free log in campaign, then I think it's best to delet them. You either have a PC or PS4, which has programs for friend keeping. There is also browser discord for PS4. You have a way to get to them out of game. I really think 200 is enough because I highly doubt there is a mass of players who regularly communicate with all 200 people on their list and would need this bumped to 300.

Communication is not a one way street. Sometimes you have to Let it Go.