I am not of fan of keel/CB boats. Just something else to maintain and have problems with (board jamming, cable breaking, etc). A Pearson 34 in our club almost sank when the fitting for the CB cable broke. I am happy with the performance of my shoal keel Cal 33-2.
That comment is really one for one particular boat in one marinia. There is no reason a keel/ cb boat would have more chance of sinking than any other boat.
Not sure how Pearson made their C/B but ours is on a cable which run through a thru hull with a stainless steel conduit attached to it with the opening above the deck. Irt is never benn hard to maintain, you change the cable as part of regular maintainence every 3 years, Takes 15 minutes. It attaches to the end of a 500 lb weighed cb. The trunk cabinet in the keel; it tucks into is wide enough and the diver says there is no more growth than the rest of the hull.
The performance you gain with a CB is noticeable to windward.
If you keep you boat on the Chessie you will find you need a diver to go down a couple times a year no matter where you keep it. We are mid to north in Rock Creek. Good bottom paint...ours is on its third year, a diver to wipe off the prop and shaft and touch up the hull is all you need. Since you are north, sometimes we go into Still Pond, and Sassafrass, and I snorkel under the boat and wipe her off as there are no nettles there.
Many good manufacturers made k/ cb boats like Bristol, Shannon, Island packet, Tartan Sabre, C&C Morgan etc. I have never heard of any great number sinking because of the centerboards.