Boost Infinite or Something Else?

By now, I would think all email batches have been sent. You can see the contents of the email sent to members with RW 5.0 plans here:

I expect the necessary code mentioned in the email can be supplied by support. All members with RW 5.0 plans are being asked to do is enter billing information.

According to the email, even if one fails to do so, members with 5.0 plans will still transition to Boost Infinite. Infinite bills 15 days after activation; so even if one chooses not to enter payment information now, it should be possible to do so post migration.