Yeah IIRC Woocommerce creates a new "Order" record, copying the shipping address from your account if you have one saved or using the one manually inputted at checkout. It makes sense that the account email doesn't update shipping email, generally companies will try to keep payment/purchase/shipping stuff in a "frozen" state or at least something where edits or logged, so in the case of issues, they can see what the user entered initially.

Same practice goes with credit cards, a charge confirmation (like something that would be generated after a stripe charge.succeeded webhook) stored in DB wouldn't be retroactively updated to new last-4-digits if the user switches the card saved in their account.