I believe that this is very unlikely, because how could a club that already had 1.3 billion euros in debt sign such a valued player?
Even if president Joan Laporta declared at the beginning of the year that "the debt is under control" and that "financial health is improving", I do not believe that Barcelona have the possibility of hiring Lionel Messi.
Also remembering that Barcelona is also facing difficulties with the registration rules of LaLiga, which recently reduced the total spending limit on salaries of the Catalan club to 648.4 million euros. To pay Messi's high salary, some maneuver would be necessary: releasing part of the current payroll or increasing revenue.
And I haven't even mentioned the investigation into the huge refereeing scandal, which could net Barcelona some more hefty fines.
Anyway... Messi will have to find another place to play.