the S7 ‘herolte’ is still a good phone but the support from /e/ for the S7 is wearing thin. It’s currently running /e/ OS ‘Oreo’ AOSP Android 8.1.0 from Dec 8, 2020 and it’s not on the 2021 migaration list. The once premium ePhone has also been delisted from https://esolutions.shop/de/. Your plan will unfortunately fall by the wayside.
There are good alternatives such as unofficial LineageOS 17.1 or experiments with GSI ROM, but a device-specific /e/ ROM ‘Q’ would be the non plus ultra.
Yes, I understand. Not too long ago, the Samsung Galaxy S6 'zerofltexx’ was also on this list. It has since been removed from the list. But there are good working LOS. 171 alternatives that are even suitable as ‘daily drivers’. No deGoogled /e/ OS but the phones will continue to be supplied with current Android security patches 2021.
If you were replying to me, I’m not actually using /e/ on an S7. Like the OP, I want to install /e/ on the S7, but I currently have LineageOS 17.1 installed and running on it. Lineage works smoothly, but I want the de-googled aspect of /e/, as I suspect most people do that are drawn to it.
Hopefully I’ll be running /e/ on my S7 soon.