To my knowledge we do not have any rules against talking about other communities. I will bring it up with the other mods.

Allowing discussion of other communities does seem to me to be the reasonable take, especially given how early days things are with Lemmy. I hope it remains allowed here. If there's a rule to be enforced, I would suggest to frame it around promotion in general. Announcing the creation of a related thing (Lemmy community or other) seems quite reasonable. Mentioning it occasionally in on-topic comments also seems reasonable (which is how I would characterize this thread). If a person or group engages in a concerted advertising campaign, an excessive-promotion rule could provide a framework to limit that without impinging on organic discussion of other F1 resources/communities.

I’m going to be subbed to any F1 sub I can find.

I certainly get this approach, and encourage folks to do what works for them. For me, I dislike getting lots of dupe posts about major news, and I think that outside of "frontpage" size communities like tech/news Lemmy is still too small to support multiple thriving communities that have 100% overlap. So I'm hoping to see people naturally self-organize into a single main F1 community and as I see this one with better governance and more activity... it's the one I'm trying to help grow through my contributions.

Niche subs with partial overlap I definitely support though. Happy to have a separate formuladank, and I'd happily join /c/McLarenMemes or /c/LandoSocials to get more on their niche. But for raceday discussion and my main source of news on the sport, I'm hoping people choose to join into a bigger community rather than have a bunch of under baked vanity communities that each lack the critical-mass to self-sustain.