At SMX Advanced, Gary Illyes said that when you do a site move, so you get a brand new domain name and want to rebrand to that domain - it can take 3 months or so for Google to pick up on all the changes. He said something widely interesting that Google tells people that it should take 2 weeks, but it really can take a lot longer.
He said it can take two weeks for some sites but for larger sites, it is more like 3 months, not even close to two weeks.
That being said, protocol changes, so going from HTTP to HTTPS, does happen a lot quicker because that type of site move is way easier for Google to map faster. It is when changing the domain name and potentially file names and URLs where it can take a lot longer.
Here are the tweets from the talk at SMX:
301 redirect old domain to new - rankings will follow. Supposed to take 2 weeks, but not always true. Could take 3 months @methode #SEO #SMX
— Brooke Fritz Willard (@bfritzie) June 13, 2017
It will take at least 3 months to receawl all the urls when a global 301 redirect for rebrand is done - moving domains @methode #smx
— Avinash Conda (@avinashconda) June 13, 2017
Some at G say it can take up to 2 wks for rankings to recover after rebrand to new url. @methode says it could be 3 mths if big site. #SMX
— Marie Haynes (@Marie_Haynes) June 13, 2017
Forum discussion at Twitter.