The tolerances you work to depend on what you're trying to achieve, and what you're working with. There's no sense in cutting something to a thousandth of an inch if the material is going to grow fifteen or twenty thousandths in that dimension over night, but if you're working the other direction in the grain, or you've seasoned the wood to the cut, it can make perfect sense.
I usually start with rough cut wood, dry it out to around 12%, plane one side flat on the jointer, square one edge on the jointer, mill parallel in the face, rip parallel on the table saw and cut square ends. I do all that a quarter to a half inch over size, then I either leave it alone for a week or put it in the kiln if I'm in a hurry. (And willing to risk losing the piece.)
As the fresh cuts (and the new surfaces) dry, the board changes shape. Maybe it bows, maybe it cups, maybe it warps. Maybe it grows, maybe it shrinks. You don't want any of that to happen after you've cut fine dovetails.
After a week, ten days, or two or three days in the kiln, I go back to the wood (usually all the wood for a small project) and speak harshly to it, demanding to know if it's finished screwing around. Sometimes it gets uppity, and has twisted too much to use, or shows signs that it's not done moving. For that very reason, in my old age, I've taken to rough cutting extra pieces, particularly with Home Depot pine, "white wood" or other known ne'er-do-wells. I've cut "hem-fir" (no such tree in nature) that sprayed water in my face at the table saw.
If it's down below 10% (I used to try for 8%, but I ruined a lot of wood trying to get there) and isn't moving, I go back to the jointer and start again, taking it right down to finish size. Plane, parallel, parallel, rip, crosscut, right at finish dimension. If it's at 8 or 9%, it's probably okay to go ahead and cut joinery without further ado.
If you buy pretty dry wood in the first place (close to 10%) it usually only takes four or five days air drying between rough cuts and finish cuts.
I've never tried to interference fit a dowel, because the grain in the dowel will run end-to-end, because a dowel that swells slightly is usually a good thing.
This book changed the way I look at wood: https://www.amazon.com/Understanding...indle-redirect