I was trying to find this exact package on the Thrive site and it looks like it's a Costco special. The closest package there is 1500 calories per day so I would assume this is close.
While you could survive on that you couldn't thrive. If you're active that could come up short quick. But if you're eating freeze dried food your are likely held up somewhere and not very active anyway.
The thing about this package is it's also a lot of raw ingredients you must prepare into meals. With MREs or MH type food it's already made for you. But after you've eaten Beefaroni or chicken and rice for a month straight your going to start suffering from appetite fatigue.