This rumour has always happened even from a few seasons ago where indeed he was still very patient at that time waiting for Deschamps to leave the French national team but that cannot happen now because after all Deschamps' contract was also extended last season so Zidane has lost his chance because France still entrusts the national team to Deschamps.
I think now is the time for Zidane to return to the club wherever it is because seeing some of the conditions that occurred there have been several big clubs in the last season offering him to return to coaching and currently Marseille is the most likely for that because it is said that Marseille and Zidane are getting closer.
A club like Marseille doesn't suit Zidane's standard cause they Lack quality players he'll be willing to work with,and might not even offer him much funds to be able to afford getting top class players for the team, however it would be very interesting for him to go back to his former club Realmadrid where he would be welcome by both club and fans with an open arms and with the quality of players currently in Madrid squad i think it might not be very difficult to win the Champions League again.
Also instead of waiting to coach his countries National team,it would've better for him to go back to his former club which I know he'll be considering, if Zidane goes back to Realmadrid the could win the Champions League and Spanish league trophy going to Marseille could be alot more stressful than the job at Madrid.
It cannot be realized with the current Marseille but it will still happen if there is an agreement between the current Marseille owner and the new Arab investor who intends to acquire the current Marseille so that they start making some initial plans including for Zidane.
In some rumors Zidane could have agreed with Marseille if in the end they were acquired by the Sheikh from the middle east especially if they immediately prepared fresh funds of around 300 million for the overhaul of their players but until now things like this are still floating because there has been no further news between Marseille being acquired whether it was successful or not but if in the end the new investor from the middle east really came in for Marseille I think Zidane could also be there with the deal they made and the abundant resources for Marseille this could make it easier for Zidane.
Barcelona already doesn't have much money and in trouble, making this transfer shouldn't really be a priority for them, not right now at least .I would say their current roster is as good as they could hope for and should let them be, just let the season end without any moves.
Do not buy anyone, do not sell anyone and just keep the season going to see how they will end. They are going to finish fine both at league and UCL, they will go to probably around quarter finals for UCL and finish either first or second in the league for sure. That is good for a team with that much debt, they need to keep that going without spending much money to feel happy, they won a title last year, they can't keep winning it every year.
This would result with them gradually having less and less debt, however if they end up getting Mitoma then it is going to hurt them a lot more and they do not have that kind of money, if they keep doing these moves then they will never be able to pay it back.
I don't know what their condition is now because their real problem in recent seasons seems to be a little bit fixable especially when they lost several players such as Busquets and Alba who incidentally are one of the players with a large enough salary to stabilize their balance sheet.
My assumption for now is that even though Barcelona are very good, they will still try to bring in players, especially for the midfield, especially with some rumors now that they are eyeing Mitoma now being one of the crowded ones but of course there must be a price to pay because when they try to bring back players indirectly this also makes some players have to be disposed of especially since they have also spent quite a lot of money before for Victor Roque who until now has not been able to play due to injury even though for the signatures of Felix, Cancelo and Gundogan this is free because of loans and trans-free.