I keep seeing this as well. Probably the most frequent ad I've seen.
Given the degree of ... social awareness... They've displayed, I wouldn't be terribly surprised if someone at Reddit simply thought "this is the perfect time for maintenance!" and they ran with it 😂
After a day of use, I'm incredibly disappointed.
The fragmentation problems, and lack of cohesive community discovery (or even apparently any agreed standards for sharing communities etc. across instances in a way the most popular app can reliably recognise as being a community and not an external link or mailto address) will make Lemmy an absolute non-starter for 99% of potential users.
I'm sure there are solutions, but as it stands I can't see Lemmy gaining any widespread adoption without a significant leap in user friendliness in regard to how federated instances are implemented and managed.
FYI, clicking those links in the Jerboa app on Android attempts to open Gmail to send an email.
While I understand the benefits of ferated servers, I think the inherently fragmented nature of the infrastructure is the biggest hurdle to the adoption of (for e.g.) Lemmy and Mastodon as replacements for Reddit and Twitter.
There is an extra layer of complexity, and the less tech-savvy users who want a simple process to follow diverse communities across many instances are going to run into issues. That group likely comprises the vast majority of potential users.
This actually tempts me to buy sea of thieves. Well played Microsoft!