Pretty sure answer is no. Older seat will not fit on newer bikes. I think they have different attachment mechanisms.
I have an older spare seat I bought years ago and it fits my 2024 T120. Online, part number T2305764 shows it fits 2016-2022 and I'll bet it fits through 25.
Didn't the old seats have a different locking mechanism - two allen bolt in the rear facing backwards? The newer seats (not sure when this started) have a pin/lock that opens using a key on the left side of the bike. I am talking about T100 and T120.
The air cooled models had the two bolts in the back of the seat. The current Gen water cooled have the lock.