First time poster - wanted to give the community a data point on my recent experience.

Marriott Rewards Chase Visa Signature

- Called Chase (1-800-338-5960) on 8/12/2019 at 8:00AM PST. Inquired if there were any current AF promotions. Customer Service agent said she could provide me a $50 statement credit
- Inquired if I could upgrade to the Boundless card and carry the $50 statement credit with me - YES
- Was told pro-rated AF ($85) from the Marriott Rewards card would be refunded on next statement, NEW AF ($95) will be charged, $50 statement credit will be applied within the next couple of billing cycles
- Confirmed will receive current promotion of 2 night free certificate up to Cat 5 hotel if purchase made on new card by 9/30
- The month your annual free night will be earned will stay the same as your current Marriott Reward card cycle - only thing that changes is the month in which you incur the AF
- Customer Service agent made it a point to say that you will lose the Trip Cancelation Insurance and 1 Elite Night per $3,000 spend in switching to the new Boundless card - noted that $35,000 spend gets you Marriott Gold level status.

Hope this helps those out there looking to get some AF consideration!