I know the feeling. I was going through my watch list recently and saw a couple of deactivated accounts, which gave me a surprise. I just wish they'd given a heads up they were deactivating, or that we got a notification when someone we're watching deactivates. So it wasn't such a shock.
In all seriousness tho I've had this happen too and it sucks every time ;; I even had a commission in with one of them and they just poofed, gone from dA and long before other social media really hit off their art communities so I had no hopes of finding them and ever seeing the commission finished. I hope they're stilll doing well... where ever they are
I hate that! That's why I save all the artwork I like to my computer. I know that's bad, but so many people I follow have just deleted their account, or at least the artwork, and I want to be able to look at it! (And no I don't upload it or anything, it just stays on my computer).
A few of my favorite artists didn't deactivate, they just stopped uploading completely but didn't say where they were going. A few of them were in the middle of uploading parts of some series, too. Blah.
That happened to me ; ; My top favorite artist left and it took me a few years to find her again. But then eventually she deactivated her new account and now I can't find her anywhere ; ; I had/have her on Skype, but I haven't used it in years because it got hacked or something one day and I'm afraid of signing back on in case it spams everyone again