Maybe that's part of the shift they are making from NPC's selling items to people needing to buy them on the Auction. Removing the NPC will allow a natural price for earthshakers to develop. Having them available from olga distorts that process.
Just speculation on my part. She also reportedly no longer sells Flaming Humbabas.
I make both those drinks and if it becomes commercially viable will probably start selling them. I'm sure dozens of other people can and will do so too.