I'm hoping for a Pokedex update if anything, so it's easier to distinguish which of the hordes are an 80% vs. a 20% encounter. I assume that whatever is more common as a single encounter would typically be more common as a horde?
From the perspective of a new shiny hunter, it is pretty disheartening at first glance since they basically increased the chances of phasing... but the flip side is getting the correct shiny in any previous 50/50 will be more rewarding than ever which I guess was the intention.
It'll be interesting to see how the shiny market settles and what specific things are valued at. Overall though, as someone that started their first shunt recently in Dragon's Den & Guidance Chamber, and is still 80k dry right now, it is slightly discouraging knowing that the chances to phase are higher than ever.