I'm unable to get any next-gen (technically 9th generation) console as of this writing. However, I'm pondering getting either an Xbox Series X or Series S (the latter more likely, as it is cheaper since I'm unlikely to use the optical drive) for testing out ports of various free/open-source games (playing retail games will come later on) that I may work on in the near future. If this doesn't work out, I could consider an Xbox One, One S or One X, though at the cost of less processing power.
Only because of the Xbox Live Creators Program and Dev Mode (thank Microsoft for these generous and official efforts!), I can actually try out porting via UWP (after I pay the initial $19 one-time membership fee, which is easily within my reach), as real certification is out of reach for almost all FOSS projects, both in licensing and cost.
If I could easily develop and test software like what Dev Mode lets me do, I could also consider getting a Playstation 5, though it will likely be the Digital Edition without the optical drive (cost is my primary reason). Unfortunately, I don't know of any equivalent programs from Sony that would allow me to start developing for PS5 (and possibly for the PS4) more easily and quickly, unless someone here knows about such a program.
A blog post I wrote just now goes into more detail about this:
https://gbatemp.net/entry/porting-oss-games-to-xbox-one-via-xbox-live-creators-program.17884/