You can transfer a phone number from that sort of account to a Gmail account. I just tried it and it seems to work. Go into settings then transfer. It takes you to the legacy page to do the transfer, oddly.
> A Voice for Google Workspace account number to any other type of Google Account, including personal accounts and accounts using a different Google Workspace domain.
I am confused if my Legacy G Suite account is considered a Google Workspace account of if it's something different.