The new counters are pretty. I would wait until the counters are installed in your lighting before making a decision on cabinet color. Are you painting them? Are you aware how big of a PITA it is to do well?

I think they look nice now and I would wait to see if the new counters give you the updated look you are going for. Some fun textural runners in front of the fridge and between the island could take some of the darkness off the flooring. I think grey cabinets with brown floors is going to look disjointed.

We have this runner in cream and navy and it's subtle but has nice texture and wears like a champ.https://www.wayfair.com/rugs/pdp/dash-and-albert-rugs-marled-gray-cotton-area-rug-dax3629.html?piid=

i wouldn’t alter your cabs. The space can have tweaks to get a more modern vibe..... seems to be your thing. Sleek hardware , modern looking tile backsplash, contemporary solar shade at the window, runner or mat of a textural or stripe For the floor...A do over w paint to all gray cabs... overwhelming work, and less durable finish ...avoid !!!

What if you did a dark grey on the lower cabinets-a shade similar to your photo examples, so the pretty new counters stand out, and have the upper cabinets white or lighter shade?

Have you considered buying new door and drawer fronts? Then you only have to paint the outward facing sides, rails and stiles. Doing the entire kitchen (with brand new countertops already in place) is a huge project. Your inspiration photos have more modern door styles, so you may want to get a price on those. Your grey colored inspiration kitchens are lovely and would work with your new countertop. The walls should be a white if you go with medium grey cabinets.