You should be able to PC without issue.
Ok I follow these forums all the time.and see these downgrade questions. Chase sapphire preferred is an amazing card. It takes 9,500 a year without a single bonus point to nullify the annual fee. Chase is an awesome bank and has great products. The sapphire preferred is clearly focused on someone who would spend a minimum of 1,000 a month, but more like 25k plus a year. To rip them off, and yes that's what you and all churner's do, is wrong. You can have 20 cards with a 20k limit on each but ill bet uve never got a call from any of them offering to waive those annual fees even before you ask. I wish chase, and all banks, would stipulate if u cancel or change within two years you owe the cost of the points back.
Oh to answer your question.. After one year you can product change.