Second, I think that, when the dad told Elaine about Monica, he wasn't thinking of his will shenanigans and that she would tell the MC and make him distrust Monica, he told her just to have her hate Monica.
And because of what exactly Elaine should hate Monica ? If the father said the truth, then :
- It's thanks to Monica if he divorced ;
- It's thanks to Monica if Elaine had the possibility to become his girlfriend, living a luxurious life ;
- It's thanks to Monica if now Elaine have a possibility to inherit of his wealth.
Sorry, but I fail to see how this revelation can make Elaine hate Monica, it's more the opposite.
Plus, what would be the interest if Elaine hate Monica ? She barely know her and have absolutely no reason to talk to her or even meet her. The only link between the two women is the MC. Yet, while the father was alive it was a virtual link because the MC haven't seen her since the death of his mother ; the father did everything for this.
But the father knew that the MC will end at Monica's house, so that the link is now active again. Yet, there's a question, how did he know that the MC is at Monica's house ?
Alright she was like a second mother for him, but he didn't had a single contact with her during 8 long years... Going back there like that... really ? "Hello Monica, do you remember me ? Well, my dad died, can I live with you now ?"
It's thanks to the e-mail that Monica didn't sent, that the MC live with her, and only thanks to it...
Anyway, the only consequences of Elaine hating Monica would be that the MC will either leave Monica, or distance himself from Elaine. The second one being already done anyway, because the MC live with Monica, and Elaine having always been rude with him he don't have a reason to talk to her more than necessary.
Which lead back to the question, why saying this to Elaine ?
The father being intelligent and knowing that the MC live with Monica, he also know that he will almost never talk to Elaine. Their discussions will be limited to the will, and was even less than that before Elaine started her attempt to befriend the MC.
So, the father gave to Elaine an information totally useless for her ; this whatever if she hate Monica (that she'll never meet) or if she's thankful to her. And he gave it to her, knowing that she'll never had the opportunity to transmit it to the MC...
No, simply no. It make absolutely no sense. Except if the father also know that Elaine will try to befriend the MC...