I take a lot of notes, some digital, some physical, some transient, some persistent.
Sometimes, I wish to take a quick note tied to an event in my (Google) calendar, such as "remember to ask about...", or "Bring up X, Y, Z".
The closest I've come is Todoist, which allows me to show tasks in the calendar, but I've yet to see something that lets me peg it to a particular event, or time.
Here are some others that might do what you're asking about:
https://www.lucidmeetings.com/ https://meetnotes.co/ http://www.meetingsense.com/ https://ecuria.io/ https://hmm.techrsr.com/hmmhome/hmmhome/home https://soapboxhq.com/ https://www.meetin.gs/ https://meetingking.com/ https://lessmeeting.com/
Some are more on target than others for your specific request, but they were all in my notes when I was researching this market for my own startup, https://reclaim.ai.
Btw, we're close to launching a couple new capabilities that dynamically schedule custom daily habits and tasks (w/ due dates) onto your calendar. We don't do meeting notes like you're asking, but we're the first service I've seen that treats task due dates as "defend my time before this date" vs "do it on this date".
If you're interested in trying it out, just drop us a note at hello@reclaim.ai :)
I have an idea for a sideproject in this space...
Doesn't attach, but uses a calendar view. Plus, it's text based.