It's possible, but not necessarily the case. Moondog's comment works fine as hyperbole in regards to his thinking Trump is excessively kissing Putin's ass without bringing "lol, Trump is gay!" into it.

And Trumping being the submissive one WOULD be bad in this context since it is essentially saying the US is the submissive one in our relationship with Russia.

Maybe Moondog was making fun of Trump by calling him gay, but there's really nothing there to indicate that and his comment works perfectly fine without it. You may be assigning him motives that aren't there.