We have seen a similar thing happen last year with the unlimited photo storage on Google Photos being withdrawn and replaced with just 20GB.
Don't rely on Google or any other free service as your only option as they can pull the rug out from you at anytime and your then forced to either spend time and money to move to somewhere else or cough up whatever amount of money they are demanding to keep the status quo.
Google will be pulling more of these sort of things in the future as their ad revenue drops so the are looking for other ways to make money from their userbase.