The latest page and what it changes is over here now: supportDOTubisoftDOTcom/en-US/Article/000072399/Rainbow-Six-Vegas-Patch and all the previous patches are over here (without a description of what they change) here: webDOTarchiveDOTorg/web/20190426195901/
Maybe the latest one could be hosted by PC Gaming Wiki itself like with the map pack? Then there's no concern of it being removed/moved from Ubisoft's site.
(Couldn't put the actual URLs even though I did reCAPTCHA just fine, had to put them like that as a workaround)