Use case or problem
When inserting a new template, it’d be super convienient if there’s a setting (or new property type variation for ‘Date’) to automatically set today’s date in the property field. I use this property inside my templates all the time and it’s onerous to have to manually set the date myself each time! 
As above
Manually open the ‘Date’ property calendar and click ‘Today’
Do you mean when you press the + New button to create a new note? There are least two options for that, currently, if you’re interested.
1. Bases fills in property values only when they’re required for the note to appear in the base.
With this filter:
note["a date"] == today()
pressing + adds today’s date to a property named a date.
Of course, if you want to see notes with other dates in that same base, then you’d have to create a separate view with this filter for creating the new notes.
2. Use Templater. It works in with Bases + New button.