Yes, that doesn't make then catholic but it does signify that they accepted catholicism as an authority. Why have a priest present if it didn't mean anything? Why swear on a bible if it doesn't mean anything? Why make these two things a requirement if it doesn't mean anything? Even though the NAZI hierarchy was involved with the occult(whatever that is) they were publicly catholic. Hitler proclaimed that he was catholic. He sought the blessing of the Pope and got it when he became chancellor. Why do all these things if it wasn't important. They didn't seek respect or recognition from any other organization only catholicism.
I haven't checked the registration of every German at the time but I would bet my last dollar that every German that joined the NAZI party was also a confirmed catholic. I doubt that any were Lutheran.
Hitler needed the catholic church. He needed the people to believe that he had divine right to rule the world. The only way to do that was to have the blessing of the pope which he sought and received. After all, Hitler was professing divinity. The Third Riech was all about divinity. The catholic church ordained every crown in Europe with the exception of England. Hitler saw himself as the reincarnation of Fredrich the Great.