So far, there hasn't been an organized recall effort. Signatures are 25% of turnout for the office, but there are complications. Harper and Riley were both elected in 2019, which means they haven't hit the end of their one year grace period where no recalls can be held.
Additionally, Johnson won an at-large seat, so the total signatures needed is not clear. By comparison, Harper's seat would only need about 650.
Update: Three of the four (Sykes, Harper and Riley) have agreed to a suspension.