Yeos,
My understanding is this (and I find myself contemplating the devas and their conditions of existence frequently):
Reading what preceded and what followed the section you quote, the basic facts are there. DEVAS CANNOT UNDO OR ALTER THE KAMMA VIPAKA OF HUMANS. They may ‘intervene’ only to provide some temporary relief, or in some cases, (unknown to us) with advice in indirect ways or to protect in dangerous circumstances, having seen that with the divine eye. Now we do not know whether a particular deva is one with magga phala. Many, if not most,are not. They are just in the same predicament that we are in; actually, in a more disadvantageous one.
Whatever ‘favours’ a deva grants cannot be a refuge, cannot be IN ITSELF a solution in any definite or permanent way. It may be of assistance ‘on the way’ but the Refuge is always the Buddha, the Dhamma and the Sangha:
Kamma vipaka will work itself out in the appropriate conditions when they arise, be it here now in the human or later in other realms. No deva (or brahma or the Buddha Himself) can come in the way of that.
So devas cannot act as ‘intermediaries’ between kamma and kamma vipaka. Vipaka will depend on kamma, and kamma is done or left undone by us alone. This is the main point.
with Metta