If the trust is named as the bene of the plan, the trust needs to receive the payments. It isn't your concern what the trust says or does with the money once it is paid to them. That said, I wouldn't want to make the decision myself as to who to pay if the trust ceases to exist - that is the responsibility of a judge, with jurisdiction over the plan. The way in which I've resolved similar issues (where it is unclear to whom the payment(s) should be made is to "interplead" the payment(s) to a court - which is essentially "throwing your hands in the air and saying I (we) don't know who should get the money, you judge, decide). That protects the plan.
You may think it is clear that the trust has but two beneficiaries - but are their contingent beneficiaires, alternate beneficiaries, per stirpes or pro-rata distributions to the heirs of the original beneficiairies and the like? Not decisions the plan/fiduciaries should be making....