Originally Posted by YOWgary

You can confirm an eUp from Lat or PYF right now, provided you currently hold enough eUp credits that will still be valid for the date of your flight. For example, if you're trying to upgrade now for a flight next July, you'll need eUp credits that expire later than the year-end date of mid-January 2024, which means you'll basically need to have earned some threshold / flight pass / etc. eUp credits very recently.

The other thing to consider here is that if you're booked in Latitude, and something happens like an equipment swap from a 789 to a 788, you'll be moved back to your original cabin, not PY. Many of us consider the added cost of booking PYF in this type of situation to be what amounts to "downgrade insurance".