Hrm since I'm paranoid. I was able to book an upgradable seat in economy and use the bxp1 upgrade pass on my flight. I was able to pick my business class seat on the app, but as I read the top part of the wiki I saw that elites and SWU/Miles/Copay are higher priority.
Assuming there's no weird airplane change, am I guaranteed that seat? or would I be bumped down if there are enough people above me?
Also does the boarding pass show that I'm in business (assuming all goes well) and I'd be able to access the flagship lounge if flying out of JFK?