Not talking about Sumup specifically here, but the whole mobile card reader market.
This is all relatively new stuff, led initially in the US where chip and pin isn't common.
The first generation of card readers were a swipe and sign type, with some having SMS verification. They were then followed by chip and pin readers, and more recently contactless payments.
The latest generation can accept payments in any way, so unless there are entire card scheme changes, or a new NFC type technology I can't envisage any more forced obsolescence. They might make the physical device better, more robust or with a rechargeable battery or something, but otherwise it already provides everything you'd need.