You want all the flooring to be the same. Tile in a kitchen is too harsh--everything will break when you drop it. Go with wood.

I'm another who would say wood everywhere. It's easier on the joints and will give a more cohesive look to everything. I don't think the narrow slats will look too dated and in fact is probably more "timeless" than any tile style.

I really like your selections, especially the backsplash tile!

The current tile transitions are not great. Once you remove the wall, having tile in only the kitchen will look worse. Personally I still love tile in a kitchen even though it's become much less popular over the past 20+ years. But with the rooms open to each other, it's just not going to work.

In an open floor plan all the same flooring always looks best in my opinion.

The new finishes you’ve selected are beautiful together/classic. If the current wood floor can be refinished to complement the new cabinetry (more neutral light stain..lighter than the island cabinetry), I’d install matching wood planks in the kitchen. While the wood floor is not trendy wide planks, it provides texture and character…especially if it is given an updated finish. I’ve had wood floors in my kitchens and beyond for the last 30 years…would never want anything else. But I’d use tile in a busy entryway…grit/moisture on wood (tracked in from dirt/rain/snow) can be problematic.

Not sure removing the wall is a good idea. Can't really provide help without a floor plan.

There is existing tile in the kitchen that will be removed

Removing tile is real work ... any chance you could work with what you have? If you do replace it, I'd definitely go with wood or linoleum ... as others have said, it's warmer, much easier on the feet /knees, and it's less likely to break dropped dishes. I much prefer the linoleum in my kitchen to the tile in my bathrooms.

but having some difficulty with the floor transition look.

This is a real concern.

Are Narrow slats ok to use still or am I dating a new kitchen?

Slat width doesn't "date" anything. Regardless, ignore trends; you'll never be successful keeping up with them. Instead, go with what works in your house and what you like (I know, following trends is easier). The flooring under your dining table looks nice and neutral. I wouldn't do a thing to it.

Overall thoughts: You have a good bit of dark brown in your house, so keeping some brown makes sense. What concerns me is that you're looking at one shade of brown for the island, one shade of brown fo the wooden floors. Be SURE all your browns are friends.

Agree to continue with wood into the kitchen - I would meet with some very good hardwood pros in your area and get 2-3 estimates - they can feather in new wood with the old wood and make it pretty seamless (we did this with an addition) -

having your flooring be consistent will make your house seem 2x as big - and make your new kitchen shine

Are there pics of the kitchen? What cabinets will you lose when you take down the wall?

Have you investigated whether that is a bearing wall?

Since your dining room is so very formal, are you prepared to change the total appearance of that room including the furnishings and window treatments?

Thanks for the helpful input. I’m more convinced on wood throughout- now onto finding the right shade of stain so all my browns can be ”friends.” Appreciate it!