First of all, petitions do not make a company or organisation forced to do what people petition them to do, so it won't mean an instawin, even if your voice is heard they can always just deny it (chance to succeed still exists though!). Hope you know this stuff works that way.
But most importantly,
I honestly expect them to instead make a new port that costs more, than to update the old one (and possibly raise it's price). Not everyone is as generous as Yacht Cub with Shovel Knight.
As for the petition itself.
The Steam Port lacks options available in the freeware version such as Widescreen support.
Vanilla Cave Story never offered widescreen either you know. Though the effort needed to make widescreen fit (small rooms can be an issue, especially with balfrog, though this could probably be fixed.). Did Wii did this...?
even a Switch release has updated features such as Local Coop, Widescreen support, new soundtracks, updated graphics (Including animated speech faces). Which is not only insulting to people who loved Cave Story where it began to exist: PC, but also insulting to other players who bought the game to support them only to be left hanging at the end
First of all why is this an insult to people who like the game from the start? It has been almost 13 years since the original cave story was released, and 6 years since the steam port. Support can be nice and stuff, but that doesn't mean you are entitled to get free game updates. It's like you're expecting to get an SNES game for free on a later system because you have the original (though the Wii U e-shop did give me discounts for games I bought for Wii Virtual Console).
and it gets even worse when Nicalis draws Quote, Curly Brace and Balrog for a Nicalis sale in Steam, they acknowledge it's existence but refuse to update it.
A lot of popular games (which includes Cave Story) on steam got stickers during the summer sale but I don't see them getting updates for that either.
Honestly I've seen even worse cases of remakes and ports that make Cave Story+ look good that didn't even get updates in the first place.
But as always with posts like these of mine, this is just what I think.