I understand your point. However, I think making the pass button as "remind me later" button can be more confusing. I mean, if you wanted to be reminded later, just close the notification.
Also, I am thinking of this in a government election standpoint. You can choose a candidate that you want (meaning you vote a yes for them and no for others) or just don't vote at all.
So, in this proposal, You actually have 4 choices: Agree, disagree, pass (I don't care. Don't remind me for this one) and ignore (not a button. Just literally close or ignore the notification so you will be reminded of it again on your next login)
The pass button is just that. It's a pass for this proposal. Like you said, either the voter don't care and/or fine either way.
I do agree on making this more accurate so I think a comment section would be good on all agree, disagree and pass votes. So, even if you pass, you have the option of expressing why you are okay either eay or don't care or if you have suggestion. Of course, comments will be optional.