There is no blanket answer to any bottle necking question as there are so many variables that it depends on which haven't been described. The easiest/best way is to test yourself. With your current GPU installed, open the intended game and set the resolution temporarily to as low as you can (eg. 400 x 400). This should reduce the GPU low significantly and hopefully shift the limiting factor towards the CPU. The FPS you receive there is your CPU's boundaries, no matter what GPU is installed.
That said, there are already benchmarks running PUBG with the i5 2400 + GTX 1050ti. Here is one, https://www.youtube.com/watch?v=9vfZCkGFGss