However, if it is, I think it's a terrible model for OSS development, or for funding development in general. I develop Cursive (https://cursive-ide.com), an IDE for Clojure code. When I was starting out and deciding how to fund it, lots of people told me I should do a Kickstarter like Light Table, another popular Clojure IDE. I decided not to and instead did the old-school thing of actually charging for the value I create. 4 years later, Cursive is going great and Light Table has been dead for years, despite obtaining $315k (IIRC) in Kickstarter funding.
So what went wrong with Light Table? The problem is that that funding is not ongoing, it's a one-off thing. $315k sounds like a lot of money, but if you have a couple of people living in San Francisco, you burn through it very quickly. When that money runs out, what do you do? It's really hard to go back and ask for more, and even if you do you're only kicking the can down the road - a year later or whatever you have the same problem again.
Obviously Cursive is not directly comparable to OSS development since it's closed-source and commercial. But the principle remains the same - development needs ongoing funding, not lump sums. As distasteful as it is to many developers, the model that best matches the actual requirements of funding software development is subscription pricing. When I was discussing possible licensing models on my mailing list, one of my users made this point more eloquently than I could:
Software is never delivered as a complete static product, it evolves over time to meet the needs of its users. Perpetual licensing leaves developers in the awkward position of deciding to support that product forever for free, or releasing new paid-for versions regularly and stepping onto the feature treadmill where you have to keep delivering 'value' to attract users away from your old versions. Perpetual licensing is bad for developers and bad for users.
As I said above, I couldn't work out whether OpenTeams is actually more similar to Kickstarter or something like Patreon. I really hope they're aiming for ongoing funding and not one-off lump sums.