I just saw the email and because it is poorly worded it is ambigious, but the bottom part clearly states starting May 1 they will charge (regardless of what until means)
So, what's changing?
Until May 1st,
You can continue using Venmo the way you do now.
You can opt to switch to bank payments at any time by following a few simple steps. Click here to switch now.
Starting May 1st for you (and starting today for new users),
To continue using Venmo for free, you must switch to bank payments.
If you still want to use your credit card, you can set it as your funding source, but you will be charged 3% to cover credit card processing fees.