Mine wasn't. I lost my main account as I couldn't verify I owned it given it was bought on a whim years ago through a giftcard, and they didn't have many recovery methods for those users. Then they permanently deleted the account after the transfer window was over. Luckily I had a second account I could transfer, but even if I could transfer the other account, you cannot have multiple Minecraft accounts tied to a single Microsoft account and having multiple Microsoft accounts is against TOS.