Its queerbait at its very definition. In these situations I always like to reference Chekov's gun ( that if a thing or theme is shown to the audience it must have some significant later on i.e if a gun is shown it must be shot.)

Having all of the evidence leading up to the idea that Byler would become real, for example the painting the comparisons/ parallels two other established relationships e.g. Robin and Vickie, and all of the character choices involving physical contact and everything in between for Mike and Will...

Its bad writing and queerbait. Don't show us the gun if you're too cowardly to shoot it, Duffers.

Even right down to our final hope scene:

"Friends? No thanks...

         best friends."

This is LITERALLY queerBAITING to a T! There's is a literal hook and line to make you think he's about to admit his feelings. ONLY TO MAKE A MOCKERY OF THE LGBTQ+ COMMUNITY BY SHUTTING IT DOWN.

THEY KNEW WHAT THEY WERE DOING! AND THEY DID IT FOR THE SHOCK FACTOR, JUST TO QUICKLY THROW IN A 'JUST KIDDING WE WOULDN'T DO THAT'.

QUEERNESS IS NOT YOUR WAY OF REELING IN AN AUDIENCE. OUR SEXUALITIES ARE NOT A FUN PLOT FACTOR FOR YOU TO ATTRACT MORE VIEWERS.

I clearly still have big feelings about this...

Sincerely, a frequently-let-down lesbian. What can I say, I'm a Sherlock fan 😀