@claudiousse
Hello
such and very similar “explanations” can be read here in the forum quite often. If you are satisfied with that, okay. But also keep in mind that other custom roms (not only for the S7) are also built by recreational developers. [By the way: The whole LineageOS Project is based on recreational work of the LOS team]. There the Oreo 8.x phase is already a thing of the past and the devs are successfully working on ASOP 9-Pie and especially ASOP 10 (Q).
My S7 herolte hasn’t been calculating with 7-nougart or 8-oreo for a while now, but with LOS 16.0 or LOS 17.1 (also with included microG apps). Here the developer Ivan Meler, who is well known in the scene, does first class preparatory work. And several ROMs are based on his performance. Also several versions /e/ OS Unofficial Pie and Q Builds, e. g. here | here and here or here.
I only come back to eOS from time to time to check the “official” statements made. And as it has been proven many times before, in reality they are relative.
Have a nice day!