Will the neet 2019 cut off decrease since 10% EWS quota seats are increased ????

Hello Neha !
This is one of the major questions in the context of NEET. Although it's quite true that the EWS quota seats have increased, but this factor is overlooked by 2 other quite major factors being :
1. Number of Examinees.
In 2019, the total number of Examinees for NEET stood at a record highest of 15.6 lakhs compared to the 13.2 lakhs Examinees of 2018. As you can clearly see the sudden huge increase in the Examinees record is bound to bring a major increase in cutoff in order to delineate the capable ones from the average ones.
2. Level of Paper.
All over the nation, many experts have shared their opinions about the difficulty level of 2019 paper and they came to a single conclusion that this year's paper was on a easier side as compared to that of 2018 which is quite evident from the fact that quite a many number of Examinees are scoring a 600+.

Keeping these 2 points in mind, it's better to believe that the cutoff is surely going to increase, be it even by a slight margin.

Hope this helps.
All the Best !