Plenty of other companies enable this by default too, such as Github, Figma, Adobe, Vercel. I think it's fair to assume that if you ahve data stored within any company, they'll by default use it for training.
Do you have any source for Github training on private repositories if you don't interact with copilot yourself?
Maybe this will become The Year of the Self Hosted.
For stuff that I don't particularly care about privacy I've kept on the cloud (e.g. my blog, which is public anyway and as such is probably training bots regardless), but for stuff that I don't want to be used to train their models and/or sell to advertisers I have moved to be self hosted on my own network.