All this is Apple releasing new product with new chips because they need to get rid of the others,
It is not as much 'get rid of others' and they need to 'have me down' these SoCs from newer systems that updated their. So Apple Watch SE 2 moves on from S9 ( SE3 moves up to S10 which got handed down from Watch 10 )
It is newer stuff coming in often from the leading edge that pushes 'hand me own" action for the products that scoop those technically older SoC and present them in a 'new' system.
Similar A17 Pro ... iPhone Pro --> iPad Mini --> (reportedly ) Apple TV .
Or entry Mac / iPad Pro -> iPad Air
At this point the Axx Pro chips are a different sized die that those chip used in the 'plain' iPhone. If Apple didn't have another placement for those chips they would just fall off a cliff after a year. The chip costs to much develop to simply throw into the trash can after only 12 months. ( the regular iPhone would be sold for 2-3 more years in addition to 'hand me down' systems )
there’s no actually changes, it’s like they need to get rid of old chips
Don't have to get rid of them as much as collect more money to cover the development costs. Makes them cheaper to make. Older fab processes also get discounts over time.
Apple does relatively precise inventory controls. If they make too many then just slow down the die making process over time. The only 'get rid of' is probably for the Studio Displays where those A19/A19 Pro are likely too defective to use in a regular system but happen to work good enough to run a camera and a speaker (i.e. can have a defective display controllers since in that context it has no 'display' duties ). The number of displays is likely so low (because so high priced ) that could just pick those SoCs mostly out of the 'throw away' defect pile with much fewer fully capable dies used.
AppleTV's SoC could be binned down also in performance. Again collected the stuff that would have been 'trashed' over a long time and use a mix of those plus full ones to complete to unit fill rate. ( probably higher units than displays. In the 2-5M range versus likely substantially less than 1M ). But this is mostly just continued production of older SoC that has been 'paid for'.