The fishing skill level does not affect what fishes you can catch.
And no fishing areas have been changed, nor has the setup for depth and bait etc for any fishes except Herbeus, Trudis and Canna, and those values are still being tweaked.
So all fishing info you gathered so far are still valid, excluding the above named fishes.
As a newcomer to the game (i started playing 2 weeks ago) that was enjoying the fishing system quite a bit this change feels like a punch in the gut,
Obviously the amount of gold you could make on the high end was nonsensical but this change indirectly nerf new fish discovery for new players the most.
Not only there are people that fished for years in MO1 and months in MO2 but now the amount of time needed to discover new fishes by guess just increased by tenfold with this change, you may spend half an hour to an hour on the right spot with the right setup only to get unlucky and miss a fish type unknown to you.
This change only makes me just want to fish on one of the main coastal cities and never give it a go to anything else unless I'm being heavily guarded and/or instructed by a guild
Experienced players and their guilds are going to contest and build houses in the most profitable fishing zones before the newbies know how to catch any other fish than a Herbeus or a Canna, In order to fish outside of cities you will need to invest in a horse to carry the weight and advanced fishing gear that is only sold in the middle of the jungle because why not, you will become a loot piñata anywhere you go to fish, many players will kill your horse and loot the most valuable ones with the only penalty of a couple of minutes being seen as a criminal by other players, if they can afford the murder count they will also kill you, making your fishing trip a huge net negative investment money and time wise.
The risk versus reward with fishing is only there if you already know what to fish, where to fish, when to fish and what bait, hook and depth to use.
A few suggestions would be adding a couple more of the advanced fishing vendor to the continent so new players don't need to risk that much whenever they go exploring with fishing gear. Also, something akin to lost pages of a fisherman journal would be nice as a catch up mechanic for new players, each page having lore and clues about how to catch an specific fish type, these could trop in content surrounding fishing spots like bandits camps near bodies of water or as messages in a bottle for example, I'm quite sure finding one of these would incite many new players to try and enjoy the fishing system.