Yeah, it's tough to pick up the pieces after a platform implodes. Have you checked out the_great_tumblr_purge, addme_fandom, or potofsoup's series of DW-for-ex-Tumblrites posts? I also see there's a sherlock_bbc and an any-version-of-SH 221b_recs, and the_good_place also has a comm-specific introductions megathread.