depends on your market but in mine yes buyers like good hardware but in the end all all comes down to price.

Personally, I don't mind closing a soft-close drawer, but it annoys the heck out of me to open them.  Maybe not all soft close drawers "stick" closed, but the ones I have experience with do.  The overall smoothness of opening and closing the drawer is more important to me, but because I also like old houses, I don't really like some of the more modern trends in kitchens.

yep, thats why I said it can vary by market. Rural Wyoming im sure is much different than SE Florida. Here in S FL everything is modern. Here buyers want 2 things 1. The best of everything 2. They want it for free 

I am adding small cabinets to go above the wall cabinets and bring them to the ceiling.  And new countertops.

I am not ripping out the old boxes.  The end panels I am making and spraying in the shop and the face frames I am brush painting in situ.  By changing from 1/2” overlay to 1” overlay, not much of the face frame remains exposed.  (A good thing, since the original was “golden oak”, and even with the grain filler, a little of the grain still telegraphs through.)

To me it generally means that the layout is unchanged and the doors, drawer fronts, and often the counter top get replaced. Almost always this also includes hardware like hinges and pulls.
Actually replacing the drawer boxes would be a bit more intense. It could happen, but really only if they no-longer work because of a drawer slide change, or replaced for wear/damage.
Here in the US, most kitchens have faceframes, especially likely for one old enough to need a refresh. That is an added complication and depends entirely on the intended goal. Refinishing or painting (re-painting) in place is common, but I have also seen veneer added.

This is what I have done for reface jobs.

Peter

My answer is do the drawer boxes need replaced.  If the drawer boxes are OK, not super duper fancy and perfect, but OK, average, fine, good enough.  Then no need to replace the drawer boxes.  But if you do a fine job on the doors and drawer fronts, and the prospective buyer opens the kitchen drawers and sees drawer boxes that obviously look much less good.  Then you need to replace the drawer boxes too.  If you go out to eat at the finest steak joint in your town and get served a finely grilled tasty steak, and on the plate is some instant mashed potatoes and the paper pouch mix up instant brown gravy.  You might think things aren't matching up.  Another analogy.  You make a handcut dovetail box.  Beautiful half or through dovetails.  And decide 40 grit is all the sanding you are going to do.  Why only do half the job good?

As for the soft close doors and drawers, I think its a question of symmetry.  If the doors are soft close, and the drawers are not, wouldn't someone say "why are the doors soft close but the drawers are not"?  If one is soft close, you automatically expect the other to be soft close too.  Or if one is regular hinges, then you expect the other to close the same way.  Its sort of a doing half the job instead of doing the whole job question.  Symmetry comes in here too.

There is also the possibility that the drawer fronts are integral to the boxes, rather than the more typical false front to a complete box.

I think that's a really good look and a great way to show off joinery, too.