They won’t be rusted, however the 3 nuts are extremely tight and made out of fairly soft metal. You can spray them all you want, but you’ll end up breaking the studs or stripping the nuts if no heat is involved…
Here is what I do-get the nut/stud cherry red with a propane/mapp gas torch (like 5 minutes of heat, lol). Break loose. Spray with PB. Re-heat, spray, loosen a little. Repeat. It sucks and takes awhile to do all 3 like this, but it’s MUCH faster than the fix for stripping the nuts or breaking the studs. They will probably come out as 1 piece (nut/stud). Oh, make sure you use a 6-point socket too.