On the other hand, being incentivized might push sport leagues into being biased. Since a lot more money is on the line, more match fixings might be created. But what about you? Do you see the pros and cons of having sport leagues benefit from sports betting?
Nah, there can't be any deep ties between these two types of business, like a partnership. One of the primary reasons is what you have mentioned above.
There can be a legal way how sports to get incentivized by bookies or casinos, and that's where advertising comes in. They can also be a major sponsor for a halftime game show or some pop-up quiz during timeouts, because that's another form of advertisement where both parties can benefit from it.