I haven’t made macaroni salad in ages, but this looks pretty good! Your relatives are so lucky!
I am normally not a fan of macaroni salad because it’s smothered/swimming in mayo with not many flavors present. PW uses only 1/2 cup mayo, red wine vinegar & some pickle juice so in addition to the ‘additions’, it’s pretty tasty. In the comments*, some folks complained about not enough dressing, but there was plenty enough for my tastes.
I used jarred red roasted peppers & had to guess how many to add - put in about a cup of them diced, then added maybe another half a cup. I used sweet gherkins & that small burst of sweet is really nice. Give it a try!
*I like reading the comments as there is generally something useful to be found, but what drives me crazy is when people say “great recipe, but I substituted x & x & x and did blah blah blah with the dressing”. So in other words, you changed just about everything except the macaroni ... & some people even change that!