The registration only reveals the model numbers of the tablets and does not specifically mention if these are the regular iPads or the iPad Pro models, but given that earlier this year, Apple already released a new iPad Air and an iPad mini, it stands to reason that whatever these iPads are, they are probably the rest of the lineup.
As for the specs and features, it’s hard to say what we can expect. Apple has largely kept the design of the iPad around, save for last year when the iPad Pro got a design refresh which gave it a USB-C port. This means that in terms of an iPad Pro refresh, expect it to be a spec bump instead of anything too drastic.
The tablets will most likely be powered by the A13X chipset, a variant of the A13 that is expected to find its way to the iPhones later this year. Apple usually saves its iPad announcements for later in the year, which means that we probably still have a bit of waiting to do.