Did Disney/LucasFilm ever actually call them Thermal Detonators? I mean if you specifically tweet the TSA and ask them if something you describe to them as a replica thermal detonator is permitted then of course they are going to say no. I think a casual fan made an assumption and just thought it looked like one to them. Really the only similarity that these In-Universe Cola Bottles have with a Star Wars thermal detonator is that their spherical.
Sorry internet--they do not look like thermal detonators!