Will my bank details update automatically after I resubscribed to my account?

Hello there, @nathan-umeda-gma.

When the subscription has been canceled, all the pending transactions will be inactive and not limited to bank feeds. You may need to refresh your bank connection with QuickBooks Online once again to get the latest transactions from your bank.

To do that you can go to the Banking tab and select the Update button to get the latest transactions. This is how it looks like:

I've added an article to show you other workarounds you can perform if updating the connection manually doesn't work: What to do if you can’t find downloaded transactions in QuickBooks Online. 

You can always tag my name in the comment section if you have other questions or if you need further assistance with the process. Take care!