StratusGrid Project Manager interview questions

First interview is with the recruiter, very simple and straightforward. Next is with the hiring manager, the current PM. After that are two panel interviews, one with two people from the dev/engineering side and then with the CEO and COO. I don't think it's typical, but I was also asked to meet one more time with the hiring manager after all that. Each interview was an hour long, except for the very last one, which was about 30 minutes. Everyone was very nice and the questions were typical for a PM position. I thought I did pretty well and vibed with everyone but I guess it wasn't in the cards. It was really, really disappointing to get a completely boiler plate rejection email after all those hours of interviewing and (assumingly) making it to the final round of interviews. Not even the position or recruiters name was included in the email, and there was zero mention of thanking me for my time or any sort of empathy. It was 100% the same email that gets sent out to those who don't even make it past the application screen. Really surprising and a huge bummer, considering how prompt and kind everyone had been up until that point.