Is there any page where Jerboa devs describes what is the policy for backward compatibility?

Since not all servers updated synchronously with new Lemmy release it's a good practice to support several older versions.

Where is the video link? I couldn't find it in the article.

It seems so.

Russia, China & UAE are quite successful with blocking VPN's. I wouldn't be so sure that in near future UK or any EU country censorship or heavy restrict VPN's.