Look, it is very simple. PL is not going to change the tickets for you without you paying the change fee. Period. There is no point in suggesting to pay part of the PL change fee; this is not how it works and it will be a waste of time on your part.
You can hope for a further schedule change (may happen - you never know) that suddenly either provide more transfer time or will reduce it further so you are undercutting MCT (in the latter situation PL will rebook you for free). However, if this doesn't occur you will take the flights with 54min transfer time at ATL which should be sufficient; even if you walk at a reasonable/slow pace. If incoming flight is late and you miss the AMS flight, DL will rebook you - it will not be the end of the day as there are numerous flights from ATL to AMS/Europe so really not much to worry about. Most likely you will be fine and on the day of departure you will find yourself on the AMS flight as originally booked.