Question

You clarified your question in a comment, I will highlight below:

My question is whether the soft theorems rule out [the] situation [of the form of the couplings is totally fixed by the graviton's universal coupling to the stress-energy tensor], even when you put no explicit coupling between the higher spin bosons in the theory.

Simply put, can we predict or explain if gravity fails to interact with other fields even when no explicit coupling is introduced? And, do the soft theorems rule out interactions even if there's no explicit coupling introduced?
A) Yes, soft theorems strictly prohibit any interaction between gravity and other fields when no explicit coupling is introduced.
B) No, the soft theorems do not affect interactions between gravity and other fields, even without an explicit coupling.
C) While soft theorems don't rule out interactions entirely, they place strict constraints on their form and strength. So, while you might not introduce a direct coupling, it must be remembered that the dynamics of the theory, especially in the context of gravity, can lead to emergent interactions that must still obey these constraints.
D) Soft theorems suggest that interactions between gravity and other fields are entirely unpredictable and cannot be constrained.

Answer 1

The soft theorems do not rule out interactions between gravity and other fields entirely, even without an explicit coupling being introduced. However, they do impose strict constraints on the form and strength of these interactions.

Step-by-step explanation:

The soft theorems do not rule out interactions between gravity and other fields entirely, even without an explicit coupling being introduced. However, they do impose strict constraints on the form and strength of these interactions. So, while you may not introduce a direct coupling, the dynamics of the theory can still lead to emergent interactions that must obey these constraints.