if you have performed no more write actions to the card (which will destroy more and more deleted data) it is possible some or all files may be recoverable. I have done this many times successfully with e.g. deleted camera images, sometimes finding images deleted many months ago. This is because most camera format actions involve wiping the fat table and leaving the data intact, giving the impression to operating systems of an empty card, and card controllers rotate memory cell usage to even wear out across the whole structure rather than write to the same cells again and again thus wearing those out faster than others.
If you google there are quite a few free data recovery programs and many pay but allowing a free scan to identify recoverable files files before you buy. I have several data recovery programs in my arsenal since no one performs better than all others in all circumstances, so it is worth trying a few to get the best result.
I have never been in the position of having to recover a technics sd card but the basic rules to follow are:
1 the files will all have numerical names and will have to be arranged in the exact original folder hierarchy, that is PRIVATE/TECHNICS/KN7000/TFLD001 etc etc, to be seen in the keyboard via sd.
2 The files are a collection of *.cmp, *.tm, *.lsw etc etc and those of the same file name must be grouped and copied together to load correctly.
3 For the above reasons it might be much simpler to copy any recovered files to the root of a floppy disk rather than an sd card structure to be seen more easily in the keyboard. They will load just the same.
4 Just make sure that each floppy contains groups of only sequential file names i.e those starting with 01, 02, 03 etc without several groups starting with 01 on the same floppy where only one will be seen in the load screen.
5 If the KN7000MN.INF or the KN7000MN.BAK files are unrecoverable you have lost all your screen file names. But the *.cmp, *.tm etc content collection files can still be loaded under their numerical names and then re-saved with a new name.
Success does depend how sd explorer has deleted the data, if this entailed a low level format (which some cameras have) it is lost forever, a high level format or normal windows delete is recoverable in the vast majority of situations providing no more writing is done to the card.
So not necessarily impossible but needing a little experience to put back on sd, easier to recover in batches to a floppy and then copy to sd and rename etc.
For general information to other readers there is nothing special about sd explorer or song manager backups. You can backup your sd card just by copying the contents to a folder or zip file on your pc, and restore it to a blank card just as easily for all data except aac audio, which should always have a backup in jukebox anyway (and outside of jukebox!)