And for this reason it's incredibly difficult to get tax-free status after the whole "new religion" movement in the 1970s. The bar the IRS sets is far higher now. Which is why this is very likely not the motivation here... any lawyer would tell you this and I'm sure this guy has plenty of lawyers.
Churches still have it pretty easy, they are excepted from having to file for tax exempt status, don't have to file an annual information return. They are not required to obtain 501(c)(3) status.
Legitimate churches, that is. The IRS is free to question your status as a church but is unlikely to if, for instance, you are part of a recognized national church organization, or otherwise function as a regular church.
Anyway, always interesting to hold Heinlein's writing up to contemporary society. Or rather, to have comparisons spontaneously appear in one's thinking as one surveys circumstances.
https://everything2.com/title/The+Heinlein+-+Hubbard+Wager+M...
https://en.wikipedia.org/wiki/The_Three_Stigmata_of_Palmer_E...