There are no lightwalletd.com warrant canary updates for April and May of this year nor I have seen any other announcements from Nighthawk or the Light Client Working Group to explain these discrepancies. The Nighthawk 2023 roadmap included, "Continue maintaining the monthly warranty canary on https://lightwalletd.com "
Per Nighthawk’s policy, " If a warrant canary has not been updated in the time period specified by us, users are to assume that we have indeed been served with a secret subpoena. The intention is to allow us to warn users of the existence of a subpoena passively, without disclosing to others that the government has sought or obtained access to information or records under a secret subpoena.