Question???

So my friend has been trying to play IW and WW2 for the last few months and it worked fine with no problem but maybe like a year ago or less, it stopped working for him out of the blue and it would tell him that the servers were unavailable for both games when he would try to play multiplayer so he thinks that activision is behind it because they want him to play the new games but I’ve tried playing the games myself on my console and they work perfectly fine with no issues. He’s tried re-installing it multiple times and nothings worked so if anyone has any ideas of what might be wrong that would be appreciated