I don't think Lucas is that conniving.
What I've come to conclude from him over the years is that he's irrational and childlike, the success of the OT is largely because he wasn't surrounded by "yes" people but kept on reigns, his early ideas were just silly. The prequels, which I'm not sure I'd say were poorly received by younger generations at least, are what happened when he lacked those guardrails. You can see his childlike approach to these things throughout ep1-3 but also in some of the commentary around other IP. He did a great job building an empire around SW and putting people in the right places, but whenever he got involved, things went off the rails.
The drama surrounding video game titles that Lucasfilm buried or redirected constantly reveals his inattention to detail, somewhat childlike approach to things, and unwillingness to move on subjects. OTOH I don't think he's really spiteful enough to sink Star Wars and all his IP, he attempted to remain involved after the acquisition and did to some degree that they allowed it. His relationship with Disney goes back into the 80s and beyond Lucasfilm IPs, he's helped design rides at the parks over the years, so Disney being the one to acquire SW wasn't exactly a surprise and I doubt he sold to them thinking it would sink, definitely not intentionally. He just doesn't have the foresight and nature to do that in my observation.
Disney also somewhat notoriously discarded his plans for the sequel trilogy, which he delivered to them (and sounded absolutely absurd). They also discarded all the legends canon, something Lucas spent decades building, I can't imagine that was well received by him. They ran with their own vision, which under Iger probably would've ended up the same way, KK or Lucas or not. I find it unlikely Disney solely hired KK based on Lucas' recommendation, anyway, and even if they had - would it have been any different? The same faults that made post-Disney Start Wars weak exist everywhere throughout Disney properties including the parks and other IP. There's no reason to think they wouldn't follow the same approach with Star Wars if KK wasn't involved and I fully expect whoever follows her will see the same vision through because that's just what modern Disney is.