Wasn’t sure where to post this so I’ll just share it with the ripcity gang. I used to use stanza.co which is what nba.com links to for adding season schedules to your calendar, but now that requires signing up and has weird ticket purchase ads in the events. Then I was using sportscalendar.net for a while, but it went down.
Eventually I figured out that Yahoo sports publishes a full season calendar at https://sports.yahoo.com/nba/teams/por/ical.ics , and this is the same for every team page there, like if you add /ical.ics after https://sports.yahoo.com/soccer/teams/portland-timbers you get a subscription link to add to your calendar. Super convenient.
For me on iOS/macOS, you add a subscription calendar and paste the url with the .ics at the end.
Bonus, they also still publish their news feed to rss at https://sports.yahoo.com/nba/teams/por/rss/