A follow up on what I wrote above...
Aside from Law 25.871 not defining a chage of status path (temporary to permanent); Articles 22 and 23 should be of interest...
Article 22 considers "permanent residents" those foreigners who apply under such condition, also foreginers who have a family connection (marriage, children, or parents) with/that are an Argentine citizen(s) (native or naturalized).
Article 23 on the other hand defines "temporary residency" for foreigners who apply and enter the country under all the residency visas we're familiar with; including migrant worker, rentista, pensioner, investor, students, etc., etc.
Thus it could be inferred from those 2 articles (and a missing clause for change of status) that anyone with those types of visas listed in article 23 is limited only to temporary residency.
But then again, DNM already had a change of status path defined for anyone carrying many of those visas in question. I do hope the new regulation decree for this law does not inferr the same as above, as that could ultimately result in the elimantion of change of status for those visas. But if that happens, I also think there might be grounds to contest it, given a path was previously established and put into effect by DNM.
/just my 2¢