Haven't been in the right place at the right time since 2020, so I don't know.
Regarding your last sentence, that's an interesting point, but the tune they play daily in Lumpini Park and elsewhere is the national anthem, which is highly nationalistic but doesn't refer to royalty at all. (Not surprising, as it was adopted in 1932 when the absolute monarchy was abolished.)
To hear the royal anthem you need to go to the cinema.