I would never have imagined in official fiction a Transformer saying "I love you" to another Transformer without one of them being portrayed as a "female" Transformer. It's great (except for the whole heartbreaking element of the context) and part of the worldbuilding exploration of Cybertronian society that is one of my favourite parts of the MTMTE series.
I'm either doing pretty well avoiding the backlash about "gay" Transformers or there isn't too much (which would be great but it's probably the former).
Chromedome's words are a mystery, I hope it was the same as Rewind's final message. The cruelest bit of the end of #15? Neither of them could read each other's lips! Argh! Damn faceplates!