You’re correct. Removing POS would making it harder for such bots to easily “get safe”.
They’d have to warp to safe spot or outpost instead.
CCP are removing POS. Citadels are intended to replace them but they’re doing it gradually to allow players plenty of time to migrate assets because POS were central to old sovereignty mechanics as well as being used for moon mining for over a decade.
A bot would still be able to warp to a Citadel to tether instead but it takes more effort in time and ISK to place a Citadel in a system than a PoS so this does raise the bar. However, when you consider how much money these bots can make and also how widespread the problem is, even this is unlikely to have much impact.
EDIT: Proposal - RMT counter