People seem to forget the GE was added in 2007, and in no way did it attribute to the decline in player activity. EoC, the garbage graphical updates and nerfs prior to EoC is what drove people away. All the way up until the MTX additions and EoC beta, this game was fine, perfectly fine.
OSRS will survive with a variant of the original GE.
If anything they need to hurry up with curses and nex.
E: As for everyone's concerns regarding the economy. Seriously, get a grip, because you apparently forget that the only reason the GE became a sandbox for abuse is because of the faulty system itself. IE: Merch clans that beyond abused it. If done right, it should be a board where like originally suggested, you can see the price, quantity and name of each player selling. "Well that will just drive the price down!" I take it some of you haven't played any games that already implemented this in-game, because it's never the case.
If you want face-to-face selling, simply lower the cap allowed to sell in the GE gold wise. On the game I currently play, ElSword, they have a 700m cap on the board, same with trading gold, but the max amount to hold in your inventory is 2b.
There are beyond simple fixes to issues that are not in any way, shape or form complex.