@Tattooed_mummy My understanding is that they will not see the toot. Their instance would have to fetch it for them to see it, but that fetch will never happen.

I've had conversations which can get confusing where people don't see the toots of others in a "thread". Especially mastodon.social is blocked by more instances than I think people realise. So it's good to be aware of this being a possibility when having multi-party conversations.