https://www.pcgamer.com/the-black-ops-4-beta-will-be-updated-in-september-so-dont-delete-it/

Did you play the Call of Duty: Black Ops 4 multiplayer beta over the weekend? Did you like it? Are you looking forward to the second beta, coming in September, which will include the Blackout battle royale mode? If you answered "yes" to questions 1 and 3 (number 2 is optional), then Activision has a helpful suggestion. 

Obviously it matters less if you have huge, uncapped bandwidth at your fingertips, but if you don't—if you had to, say, pull an overnight download to get it onto your PC—then not having to do that all over again in a month is a pretty big plus. Obviously you'll still have to deal with a download of some (probably considerable) size, but an update is bound to be a lot less chunky and time-consuming than a full reinstall.