I have no clue about Grundy's canon associations but to me it makes sense. In most versions he was murdered in a swamp and came back to life, I believe the wiki mentioned something about how he could've become a full elemental had he not been tainted by the grey (the domain of rot and decay).
If you will allow, I would like my version of Swamp Thing to have not associated with any versions of Justice League up until this point. Apart from that, I will add to his history when I can.