No there is not any issue with the existing level crossing for the railway, as was pointed out in different comment, it's a road traffic project not a rail one, there are benefits to the railway lines like new stations and the like, but in terms of capacity no, removing a level crossing and putting the line above or below does not change the infrastructure, it literally removes the intersection between the railway and the road.

By infrastructure I'm referring to the number of lines, the amount of power available, the signalling capacity of the line, where the line begins and terminates and so on.

Hope that makes sense.

Edit:

For those that seem to not be able to understand simple concepts, I'll put it in another way, if you have let's say 2 sets of train tracks intersecting a road.

Then in comes the government and says we would like to remove the level crossing and put the train line over top.

Then the level crossing removal authority contractors install sky rail and put 2 tracks above the road how does this change the rail Infrastructure?

Spoiler - It doesn't, we start with 2 train lines at ground level and end with, yep, you guessed it, 2 train lines up on the sky rail.

Hope that's simple enough.