I was speaking about rankings (rankings do get back to normal after a while), not about the "submitted not indexed" thing that you see in GSC.
oh, don't worry! You're gonna dance how google signs for your entire life... or until google disappears, so be prepared for this shit year after year. As for Bing, even one of my non-SEO optimized sites ranks on the 1st page of Bing for 2 keywords (each of them gets less than 100 searches per month) without me doing anything about it. The domain name is an EMD (very similar to "learn guitar lessons", but obviously not this one). So, trying Bing is not something that you have to prepare for, cause Bing is not as strict as google. If your sites are optimized for google bing will just rank you outright. I guess you still need to submit your site's sitemap to their search console, but I haven't done this and I still rank. So, I don't know....
And yeah, google is uncertain... well, all 3rd party tools, sites and services that directly affect your sites are uncertain. Can you bet your house on a nickel that SEMRush will stay forever? Or Ahrefs? Its the nature of this industry (SEO) that makes it volatile (I hope I used the right word
) ... Anyway, apparently you are a much more experienced SEOer than I am, so I don't think any of my "tips" are eye-opening for you. So, all I'm trying to say is that you should just diversify your portfolio of sites, and the SEO efforts too. Even I, as poor as I am, still have 7 sites (1 authority site, 3 autoblogs, 1 ebooks store, and 2 blogging mom type of sites) that I'm "working" on (by "working" I mean I post an article on them once in a blue moon, if I'm in the mood lol) and at least 3 more sites (2 autoblogs + 1 authority) will come by the end of this month cause you never know what sticks and what takes off. So, diversify, use white hat techniques, spamdexing, autoblogging, etc and whenever one method stops working other methods usually get better. That's why it's better to have different types of sites and using different SEO tactics. Either this, or let's go pick cotton