I don't know where you've been but pros are ALWAYS changing their cues and it's not because they found a better one. You start with point #1...pros need the money. Then point #2...pool players like FREE(don't we all). Somewhere in there, a deal is struck. I remember Mika playing with some of the crappiest cues I ever saw, and oh btw he just happen to have a bag full of them that he'd be willing to part with at a price. Those are the kinds of deals that are struck, whether they be play with pay, sponsorship, cue give-aways for resale,,,it's been that way for decades. All players in all games seek sponsorship, in pool especially because of the lack of funds.
What, you think the pros are rolling in cash that they can afford to turn down a deal with cuemakers? You think this kind of thing is not done in other sports? In OTHER BUSINESSES?
The cue a pro like playing with is the one he's playing with NOW, and tomorrow it might be a Meucci.