Down 48 on Wegovy and my arms did the same early sag thing around 25 lbs gone, then slowly tightened up once I'd been lifting for a while. Stomach took way longer and I wouldn't judge it until you're actually at goal. Give the strength training a few solid months before you stress.
Loose skin at 20 lbs down - what to expect
Only 8 lbs down myself so no sag yet, but this thread is making me want to get back under a barbell before it shows up. Sounds like arms bounce back quicker than the belly, so I'm filing the stomach panic under "later problem."
Mine didn't really fill in on the arms until I'd been lifting consistently for several months past the loss itself, so patience matters more than anything. At 2 lbs down you've got a long runway, so I'd just start the strength work now and save the real assessment for goal weight.
Down about 3 on compounded sema myself so way earlier in this than you, but I started lifting the same week I noticed the first bit of looseness figuring it couldn't hurt. Seems like the consensus here is arms recover and belly is a wait-and-see, so I'm treating goal weight as the real judgment day too.