The insurance being discussed is Accident and Liability insurance. Look at it from a business standpoint.
The field owner will require the team to have insurance. The tournament organizer will require the team to be covered by insurance. They (The tournament organizer) may buy insurance that covers all of the teams, but the insurance company may deny coverage for the teams that have violated mandates in order to travel to the tournament. Surf Sports will have some language in their application that says individual teams are responsible for being in compliance with all applicable rules in an attempt to insulate them. The CA based club ends up being on an island. The covid waivers they make the parents sign might be invalid due to the club being responsible for the participation in the tournament. This is why clubs decide they won't risk it from a liability standpoint. The Board of Directors may find that their insurance is invalidated if they allowed a team to travel out of state as a representative of the club. Workers comp may be invalid for any injury to the coach ( provided they are an employee of the club). This is what leads clubs to decide not to participate.
From US Club Soccer
Q: For an activity that takes place in a different municipality or state than the member/member organization resides or is based, which local and state public health requirements and orders are applicable?
Members/member organizations are responsible to ensure they understand and comply with the requirements and orders of local and state public health authorities applicable to their activities. This means that a member/member organization must comply with the rules and orders of the locality(ies) and state(s): (1) in which the member/member organization resides/is based; (2) where the activity is held; and (3) through which the member may travel while the member is in that locality or state.
Q: What if the applicable local and state public health authorities have conflicting requirements/orders?
In this situation, US Club Soccer encourages members to consult with their local and state public health authorities and legal counsel.
We recognize that does not answer the specific question of whether an activity is sanctioned by US Club Soccer and therefore covered by US Club Soccer-provided insurance. However, given the unique circumstances of each claim and the particular issues that may exist between local and state authorities, our insurance provider cannot provide a blanket determination. Our understanding after discussions with US Club Soccer’s insurance provider is that the insurance provider would take into consideration whether the member/member organization acted reasonably in such a situation.