Hi. Happy New Year.
That's an interesting situation if there is no contingency. That would be odd frankly - really odd since most grads look for other opportunities as it never hurts to look (e.g. BCG and other MBB's will require 2-3 years of work after graduating in exchange for being sponsored).
I don't know about your situation but seems it would be the right thing to do to continue working for the same employer. In terms of what you would be losing and missing out on, it is on-campus recruiting since you can't go back on campus a year later after graduation. All the connections that second years or Career Services may have for you.... but they may or may not be meaningfully better.
One option you can have is recruit during school and compare the options and offer to pay back your employer if you don't come back a portion of the tuition or whatever separation agreement you may reach.... but I would say recruiting is a double-edge sword. During the 2 years, every single of the students will envy the ones who are sponsored and coming back to their employer. They have an easy life that is worry-free and heavnly. Everyone else is going through FOMO and crying at night. At the same time, after 2 years, and being comfortable, you will see your classmates who will be walking proud and tall and excited having grown a few feet, looking forward to their new jobs, bonueses, etc, and then the roles will switch. You will feel that you have missed out on an opportunity to grow and it will be somewhat boring to come back to the old job... of course I am being a bit extreme in the story but there is at least 50% truth in it

P.S. I would be surprised if there is no strings for M7.... but that's awesome if that's how it is. You have the best of both worlds really. A Free MBA without a contractual obligation.