I noticed this a while back, but honestly it's all by Dr. Luke and Cirkut, so I don't think it matters much. All three are great, catchy pop songs and I doubt most people will notice or care.
Also, B.o.B. and Taylor Swift's song Both of Us has a very similar bass synth. Also produced by Dr. Luke and Cirkut. If it aint broke, don't fix it.
I don't agree with these criticims, if indeed that's what they are. Electronic dance music is all about taking the same effects and loops and other components and putting them together in different ways to make something unique each time. It's interesting to notice how and when this is being done, but as a criticism to me, it would be like criticizing rock 'n roll for reusing the same 12 bar blues all the time.
For all of these songs, the end result is that the songs all ultimately sound very different from each other.