While I dislike Picard and Discovery more for their writing than retcons and it's true there has been hiccups in continuity before Discovery by claiming to be the original timeline feels more like a Reboot than the 2009 film reboot of the Franchise. At least shows like TNG with Relics, DS9 with Trials and Tribulations, VOY with Flashback, and ENT with Into the Mirror Darkly visited that era or it's technology tried to be faithful.
To be clear though I don't care honestly because I can ignore all the Trek Kurtzman has made and just watch TOS, TAS, TNG, DS9, VOY, ENT, & the 13 movies (Yes as noted im my movie list I like the JJ movies change doesn't bother me). Just commenting because the retcons on Discovery in particular are so glaring.