The willingness of Olympus to stand pat at 16MP is one of the things I like about them. they don't seem to be compelled to turn-it-up-to-eleven.
On the other hand, for wildlife and bird work, resolution is king. You always are cropping and you always want more resolution because the little critters rarely come and perch on your studio portrait stool under perfect light.
I slightly disagree: the benefit for wildlife photography that you attribute to the cropping latitude given by more pixels is more specifically the benefit of smaller pixels, and thus high angular resolution from a given focal length. The other way to improve resolution on a given small/distant subject is of course longer focal lengths.
If you stay with one format, the pursuit of smaller pixels does indeed mean needing more of them; often a surfeit of pixels followed by heavy cropping. But what I like about using a smaller format system like 4/3" for wildlife is that you usually get those smaller pixels
even though the pixel count before cropping is a bit lower, and so a somewhat shorter focal length gets the job done. In particular,
Nikon One at 14MP > MFT 16MP > highest current APS-C resolution > any current 35mm format camera
for the wildlife reach of a given focal length.
So what MFT currently somewhat lacks, and Nikon One severely lacks, is good long telephoto lenses that are native to the system and AF well with it. I am fairly happy with the Olympus 75-300 (”150-600 in my coat pocket") but brighter long telephoto options would be nice, which is why I am hoping that MFT PDAF will revive my 50-200.