No, they are not special, it’ll be fine

leap second corrected or not?

The first one would have deleted nothing as it needs to match the whole name. I recommend running find with an explicit -print before replacing it in place with -delete or -exec. It’s good to remember that find has a complex order dependent language with -or and -and, but not maybe the best idea to try to use those features.

C preprocessor wouldn’t care about it

All instruction sets are documented in English and it’s more esoteric so the tutorial scene in any non-English language is less developed, so that requires even more English skill than memorizing a couple of keywords in a mainstream language.

Dynamic yes, objecting to 24h. Many places keep the same dynamic address for months or years

Maybe yours does, but that’s not universal in the slightest

Jellyfin was forked when emby went closed source, I don’t think it had anything much to do with any specific event at plex

You don’t have to give contact permission to the app.

Don’t give it internet access during setup.

I think there is, but AFAIK they can use it for something very minor and it still counts.