Welcome to the forum, but that was not the most impressive first post. It ignores the bolded and large beginning of the post:
This was saved when the WotC forums shut down is 2015. It has not been taken over by the owner and Mistwell isn't trying to claim RhaegarT's work as his own and update it.
Tidal Wave came out in Xanathar's Guide to Everything that was published in 2017, would most definitely not be there. Nor would any of the other XGtE spells that Sorcerers get, a fairly large list which you missed in your criticism.
Alternately, if you looked at the Google Docs version, which is getting maintained, you will notice that Tidal Wave is listed:
Regardless of the history, a more positive introduction to the community would be "Hey, I noticed this spell isn't there so here's a write-up and a rating so we can improve this". Community feedback is common, take a look at the various guides here.
As it is, it comes across as bragging that the only reason you bothered to create an account was to call out someone's mistake. Which really wasn't one.
Looking forward to having you as a positive member of the community.