This is quite exciting in that it removes plastic waste. I see no reason why different companies can’t make different shape ones to maintain their lock-in. I expect a knock-off market to pop-up, but that exists with plastic pods too. It’s a step in the right direction at least.
FWIW I use a regular drip coffee maker and I only ever make a cup per day. I fill my coffee mug and dump it in the reservoir, then use one of the smaller size filters and one scoop of coffee adjusted for the size of my mug. Though typing this out, I’m now thinking of getting a reusable filter basket.