For what it's worth, Wada probably isn't lying about the "cut" original Yosuke Romance just being debug voice lines.
There's zero code, dialogue, or text in the game files beyond those few audio files. There is no "full and ready to go cut romance" like so many people have said, it's just not real.
Atlus USA wouldn't discriminate between used/unused, which is how you got it dubbed in both languages. You can corroborate this by looking at the many unused dialogues and system messages which were also translated.
As for the Yosuke "break" dialogue with Yukiko, most datamines point to "Jealousy" having been a mechanic for the Investigation Team's trust of eachother, not the Protagonist's relationship with romance partners.
My initial theories were either "it's debug" or "it worked like FES/was forced". If Atlus thinks it's debug, that's probably correct.