My understanding is that cutter and slider are essentially the same pitch thrown at different velocities. Similar action, similar spin. Fangraphs "Pitch Type" has him abandoning the slider but with lower velo on the cutter, but "Pitch Info Pitch Type" has him still throwing 5% sliders but higher velo. So, just depends what coding system is being used. Sounds like in Grayson's mind he is still throwing a hard slider but it may be ticking up in velo.