It's support or agreement

I'm not sure, it's usually used as a business term to buy shares when you're not part of the business I haven't heard it being used like that before I'd assume, if it can be used there, it would mean to aquire a piece of information you're not subscribed to or have not been part in making And instead of using Is it mean Use Does it mean

I've never seen the term buy-in used in this manner before but based on the context, it seems they are using it to mean "constructive insight".