BBTS:
I looked at the link, which--in the case of NYC--isn't much more than you copied and pasted.
I think I can conclude this:
4.5% of the NYC COVID-19 deaths have been people who were under 65 and had no underlying medical issues.
89% of all age-group members who have died have had underlying medical issues, but we don't know the rate of underlying issues among either those 65 and older or those younger than 65.
Therefore, we can't really say that 95% of the NYC COVID-19 death toll is coming from those 65 and older.