Should I be concerned at what he's watching?

Yeah, you should worry.  In just the last few years my TV watching has successively made me into a cannibalistic serial killer, the queen of England, and a magically-mutated monster-hunter.

I'd TBH keep your thoughts to yourself about this because it makes you sound kinda homophobic.

Different people find all sorts of shows entertaining for their own reasons. While I would never personally watch these shows, and I do think it's kind of weird that he likes them, I don't think there's anything inherently wrong with it. Shows can't make you gay and, unless he's been in the closet his whole life through marriage and having a child, I don't think you have anything to worry about. There's probably some aspect about them that he finds entertaining. To that I say: 

You're going to catch your husband on all fours, with the pool boy riding him like race horse in a few months. Mark my words.

Hola! Como estas? Orthodoxy is the only true faith. How to know if a church is truly Orthodox or not (that is, it's following the antichrist but claims to follow Jesus)? Orthodox has one Jesus cup with one Jesus spoon; priest finishes what's left in the cup after all the sick people ate from it (he never gets sick obviously). Some "churches" recently said that they will not allow one cup one spoon during the Coronavirus pandemic ("COVID-19") [obviously, these are not truly churches and don't have Jesus there (they have antichrist's blood there with hexagram on bread instead of normal IC XC NIKA cross/8sided star of the Mother of Jesus)]. For some, the language in this paragraph will be unclear... sorry then. After China attacks Russia, resurrected saint Seraphim of Sarov will show new Ruski Orthodox Tsar who will slay traitors; currently 300 bishops in Russia; 3 bishops will remain and 297 will be killed as they are traitors. Antichrist will claim that Ruski Orthodox Tsar is too strict (ala saint Tsar Ivan "the Terrible" who didn't kill his son and who did 1200 earthly bow downs each day and now is singing "HOLY, HOLY, HOLY" with the Cherubim/Seraphim). Thanks for reading; if you don't understand the wording; sorry, forgive me. Adios, Amigos!

If your concern is that he's embracing the downfall of quality entertainment and adding to the numbers that convince networks this is what we all want to see your concerns are valid. If you legitimately think watching this tripe is going to make him gay or cause him to want to do drag you're probably losing your mind. 

He is right - it is just entertainment. I have watched some episodes and I am a straight woman. Its just entertainment, as he said. You shouldn't make more of it. 
Perhaps he wants to watch so he can join in the conversations about it when they get together? 

I agree that watching so-called "reality TV" is disturbing.  It's a sign of low class and low character.  But Pose is scripted TV.  A person can be allowed one or two junk food shows without it impacting them or making them trashy people.  

     At first glance, it seems benign enough but I got to thinking about it and I realized this stuff makes people desensitized to that part of the world. For example, since I read your question I looked it up and found it was about homosexuality and transgender.  Your husband had to watch it a while to adjust to it. But he did, and I think that might be the whole purpose other than making money of course. If we become desensitized to it , It will become an accepted norm. If you want to worry about something think about how it will be for your grandchildren in the years to come when little girls want to grow up to be drag queen. We are on a downhill slide America. Grampa B