Not sure you are correct about Chase not letting you opt out of the Freedom card during the transition. I called and successfully closed the still unsent Freedom card account after Chase transferred AGR card data to the new Freedom card number. In other words, the AGR/Freedom cc was closed and I will not receive a new card since I let Chase know I would not activate any new Freedom card they sent me.
That is absolutely correct. But if you wish to retain the line of credit for purposes of gussying up your FICO score then that purpose would not be served by canceling the card, unless you could transfer that line of credit to some other card.
Chase actually offered me to transfer credit limits card-to-card a few months before the AGR change. I had an old "low-rate" card with a big (for me) limit, the CSP and the AGR.
So shuffling limits around between different cards at same bank is possible.
"Gussying up your FICO score" -- it's getting more difficult to do that -- maybe with the old, now cheap, original FICO score (that's the one I see (for free) on my CSP and Discover card accounts), getting higher and higher limits might help.
BUT, now, there's maybe a dozen different FICO scores, for each Credit Bureau, for different "target consumers and lenders" *
If you want a good credit score -- as the free credit reports note- do "Paid in full, never late".
If you like a 5% rebate better than 2% or 1%, for what you are buying now, maybe the Chase Freedom is a good deal.
*(I recently applied for a home equity loan, and the lender disclosed the credit bureaux and scores, none of which matched the "FICO score" that Chase gives me monthly. They were all "FICO+(subscript) scores -- and ranged, not in points, but in percentiles, from 78 to 99
) (I got the loan, at a good rate, but ???)