I have shoot sports on and off for 30+ years, and really liked this article. Mr McDaniel sums it up well in the first paragraph: If you have equipment where iso 3200-6400 works, particularily after a bit of scaling down, and pair that with f2.8 or faster lenses, you can shoot almost any indoor sports event.
Today’s m43 cameras do that well, meaning they are indeed useful for indoor sports photography.
Usually when someone brings things like this up it erupts into a debate why cameras like Canon Eos 1Dx and Nikon D4s at all are used when you obviously can shoot even tricky things like indoor sports in bad light with much lighter/smaller/cheaper equipment.
Well, as I wrote, a m43 camera is indeed _useful_ for indoor sports. But a 1Dx or a D4s is way _easier_ to use for that. As a professional you want the maximum yield of useable images from every situation in every event since you must always deliver.
BTW, I strongly recommend rollerderby, it is great fun to watch and to shoot.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.