The Well Tempered is a rather unique design, relying on the silicone bath to provide dampening and support and a pivot point of the "bearing" on the arm. It is rather critical to the design. If he was worried about overdamping this arm then he should have, as an engineer, built in some live ane liveliness in another manner. I haven't heard the new table and arm, but I have heard the old one and it is certainly not lacking in excitement.
But too much silicone dampening of other arms, where it is not a critical component to the support of the arm, can certainly cause an overdamped and unexciting presentation. Use silicon with caution and be prepared to pull it out again if you lose that energy that makes music come alive.
Enjoy,
Bob