The policy should name whoever holds title
When a house moves into a revocable trust, the owner on the deed changes even though nothing about daily life does. If the policy still names only the individuals, the party with the insurable interest and the party insured are no longer the same, and a carrier can raise that at a claim.
Adding the trust is usually straightforward
Most carriers will add a trust as an additional named insured on request, frequently at no cost. The difficulty is not the process, it is that nobody tells the insurance agent when the estate attorney finishes the paperwork.
The umbrella has to follow the underlying
If the homeowners policy names the trust and the umbrella does not, the layers no longer describe the same arrangement. Both need updating together, and that is the step most often missed.