I think that with such a good squad, Atletico Madrid should not continue to lose at such a pace and continue its terrible streak, so it's not a fact that Barcelona will get ahead of Atletico.
Atletico has a problem with player injury, it makes them difficult to show his best form. If you checked their squad, there are some injured players lately. Savic, Gimenez, Vrsaljko, Llorente, and Griezmann are injured, they cannot play temporarily. Losing Savic and Gimenez is the main problem here since they are the best Atletico central backs. So, we cannot blame them to get bad results because they are not as strong as you think now. Regarding the chance for Barcelona to overtake Atletico, it is very possible since the point gap is only 1.
Overtaking is a common thing and I think there is no problem with that because after all, they will continue to play throughout the season and we will just have to wait for the final standings. With both Atletico and Barcelona improving and dropping so far, the reality is that they still have a chance of finishing in the top four, so if it was just about overtaking it would be fine if they could finish in the top four in the end.