The DW is a barrier between the range and sink when the door is down. Since it appears there is no room to put it to the left of the sink, I would put the sink in the island, offset from the range with the DW to the right of the sink. May also want to consider a large single sink rather than a double.

My dishwasher is between my sink and range and has never been a barrier. While I understand the potential, depending on how one cooks, I would not move my sink to the island just because of this. I like having my island free to prep or put finished dishes on.

If your in-laws hope to be in this home a long time, I would not do a microwave over the range. I wouldn't do one anyway because they vent poorly and crowd the cooking area, and I am short. My elderly mother can no longer reach up to her microwave. If they can afford it, they may want to look into the microwave drawer and place that in the island. I don't have one but those who do seen to really like them though I understand they are expensive.

I might consider changing the pantry to a simple upper and lower cabinets and place a small microwave on the counter there. I might also consider that because there should be a "landing space" close to the fridge. The island may be close enough, but you want something an arms length away - for when you need that item that is pushed behind to the back and you need to pull things out to get to it.

I agree with jhmarie in this case (and I also had no choice but to locate my DW between sink and range). If the DW and sink are on the island, there will be very little prep space beside the sink.

I also like the idea of landing space beside the fridge wherever possible. If you make the base cabinets on each side of the range drawers, rather than door cabinets, you can squeeze in some extra storage--unless one is a trash pull-out; if that's the case, a trash pull-out can go under the sink.

If you must have the tall pantry cabinet, and if there's a possibility the stub wall could be omitted, the fridge could move right, with a side loading pantry.

I somewhat agree that the DW can be a barrier, I think in this case though, the sink is better where it is presently. Putting the sink in the island would have more complications being directly across from the range & in all honesty, whether it's in the island or next to the sink, the same barrier is present.
You're in your DW fewer times than at the sink & range. Having the island clear of obstacles serves well for a buffet set up during entertaining company.

Just make sure you have enough space planned between the range & island & the fridge & island. Given your space to work with, I don't think it's a terrible layout.

I second mama_goose on the wall to the left of the fridge as well as a garbage pullout.

Hard to know if it's the best layout without seeing the rest of the adjoining rooms, but it looks ok except for some suggestions;

1) Bring the cabinets all the way to the ceiling by going with 36" tall cabinets, stacker and crown

2) Make sure the corner cabinet is 36" and not 33" because a 33" cabinet has such narrow doors that the cabinet is a missed opportunity for large mining bowls and small appliances

3) I would also not put microwave there unless they are on the taller side and you plan ahead for the microwave to actual vent out to the exterior.

4) I also would make sure the island is composed of drawers as they are easier to get in/out of and hold more

Maybe switch fridge and stove so that dishwasher isn’t between sink and stove.

Those pics aren't very clear. But there is room for the stove on the fridge wall. It would have to be a corner cab (38), range (30), cabinet (12), fridge (36). But it would fit. i think that would be a better spot than beside the dining area, yes?

Don’t put them both on the same wall, switch them.

If your in-laws are over 60 or will be soon, they should consider a wall oven, microwave in island and range top.. bending to lift from an oven and reaching high to move something from a microwave becomes more and more difficult with age.