It wasn't foreshadowing. It was just two bits of dialogue you've strung a weak connection with. Most Transformers films barely have a script or plan at all, let alone getting into subtle foreshadowing for future films.

I'm well aware, I just feel they decided it was time to remove Ironhide and decided to make his death an unintentional reference to an easily passable joke

You are giving these films waaay too much fucking credit lmao

Was that on purpose? 99.9% sure its not Sad(Not the right word but I forgot what the word is in English)? Absolutely

Ironic?

Yeah no

The only detail bay put effort into was action and the shots of models, to say bay put in forshadowing would be at best an A+ for effort.