Aloha,
yes, it is a phase. Both my kids, as babies, when through that. Most do. It will pass. Don't worry.
Just make sure, that when changing his diaper, since he is squirming around more, that you change him on the floor. If not, and you're doing it on something like a changing table or bed etc., they can fall off/roll off. This seems common sense, but it does happen.
For me, when this had happened, I changed my kids on the floor, using my 2 legs to straddle them, holding (gently) down their upper torso or arms, then QUICKLY changed their diaper. Or course, making sure you have everything you need right there.
Yes, they will scream, but it can't be helped. You gotta change their diaper. Also, sure you can say "just a moment..." or "No." or etc. But, they will still scream or squirm.
It WILL pass though. It's all about ages and stages. More phases will come up. Another phase my kids went through when a little older, was when it was time to change their diaper, they would RUN away... and run away... and they thought it was SO funny. It was hard catching them! They would laugh the whole time they were running away from me. Oh well. Stages and ages and phases. And it took time to actually catch them to change them... and especially took extra time if we were about to go somewhere and the clock was ticking away! LOL
Good luck, they all do this, it's common,
Susan