It is time for other US carriers other than T-Mobile to support the Samsung beta program. Everyone that has the phone that they are running a beta on should have access if they want the beta. Not everyone get an unlock phone or have T-Mobile. I also have a pixel device and I'm able to get the beta programs no matter what carrier I have. Samsung should push this so everyone has the opportunity.
Carriers have to opt in to allow beta testing - none of them are forbidden from doing so by Samsung, they just choose not to participate. Take it up with your carrier if being a beta tester is that important to you (or switch to T-Mobile, since you know they participate).
