The diary was sent to the MC by his grandparents most likely, it was something related to Lynette's wishes, I don't remember the exact words at the moment.
Or it might have been sent to him by someone else, like Stephen for example. Stephen (and Jade for that matter) probably knew Lynette and respected her wishes, so why shouldn't they be like secret beneficiaries to the MC during his studies at B&R? I've said it before - Stephen might not be the ultimate evil/bad guy that we all think him to be. He might not even be the guy the tuition girls are supposed to fuck.
I am so confused right now. What do Stephen and Jade have to do with Lynette ? How did they "probably" know her ? And how does the MC have a beneficiary ? Did I miss something ?
The canon that I know is : MC sleeps over at Bellas place, gets a message from his dad that he got mail and that its stuff from his mom. So that rules out that it was any sort of official inheritance, cuz you dont get them by mail, you have to accept it with the option to refuse it and you actually have to do it personally.
And in general, I think we know that the family of the MC's mom was well off, but if you buy a Hotel and then move to live in it WHILE its beeing renovated, you are 99% of the time NOT Royce, Burgmeister or Burke rich, as depicted by how those 3 can spend money without a second thought.
And about Stephen, all we know is that he fucked 3 Students, Cathy and 1 woman before that, which made Jade suspicious for the first time. We also know he is re-al-ly trying to get into Bellas pants and that when he sees his wife beeing fucked by the MC in a vid, he is "happy".
The question I want answered the most is, who the fuck sent that package with MC's moms diary and the 5 grand. I agree that a family member of Lynette seems like the obvious choice, but then the 5k indicate that they are doing much worse than everyone seems to think, cuz if someone ( like a grandma or grandpa ) is guilt triping, you dont sent 5k, when a private dance with Nicole already costs 40$, if you are really loaded.
But who else could have her diary ? Her bff or a sibling ? It's probably on the last page in the damn thing and we have to wait for the answer for 2-3-4 Episodes...going crazy.