Following the dreams!!
That's exactly what my issue is bro! See, there are two possibilities here:Um but how did Red Eyes thing didn't go anywhere? Rey Eyes rage mode only activated when Lycanroc gets drenched on smeared with mud. Later on in the battle with Tapu Bulu, Lycanroc was thrown into the water, but it didn't activate rage mode that time, showing that Lycanroc's issue with getting dirty/wet, which leads it to activate rage mode has been sorted out. So yeah, Red Eyes thing has been sorted out once and for all in this episode.
1) Lycanroc doesn't get mad when dirty now. So red eye thing is gone and this was the last time we saw it.
2) Lycanroc has learned to control his anger. He doesn't get mad when dirty, but there are other things which can bring back those red eyes back.
If it's the first case, then i must say that red eye thing has gone nowhere. It could have been something like chimchar with blaze, where the red eyes actually increases it's power or maybe like psyduck with headache, where it can use some attack only when mad. IIRC, even you thought the same thing, that it would be wonderful if this beserk mode gives some kind of power-up to lycanroc. But no, it was just getting mad becauss it was dirty losing the important battles in the process.
But if it's the second case, then writers can still do something with it. But chances are very low for this.