I'm thinking they considered this strongly, since that's what they did with the steam deck.

We don't know price yet, but if it's like the deck they'll be trying to keep it as cheap as possible. The deck supposedly was so off-the-shelf that it re-used a design for another AMD customer, leftover elements and all - https://boilingsteam.com/an-in-depth-look-at-the-steam-deck-...

Unless Valve took a big risky bet, the Steam deck is going to be again re-using existing hardware and excess hardware. I'm presuming there are leftover unsold Zen 4 and RDNA 3 dies - and nothing competitive that AMD could offer from Valves perspective, at least when they locked the design some months ago.