Devas, when considered within the 31 planes of existence, are a somewhat troubled reading.
I explain.
If I have understood Buddhism correctly, everything in this world is just fabrication.
And gods (devas,) other creatures (yakkas, men, etc,) are part of these creations.
Karma (a.k.a. Viññāṇa - [the support consciousness (that) is for the purpose of future rebirth. SN 12.12]) is the factor of samsaric creations.
The product of the aggregations of Sankhara Khandha elements (namely bodily, verbal & mental determinations) diffuses through that "support consciouness," to deliver the existential being (through the process of Name & form, organs of senses, contact & the rest.)
As far as devas are concerned, they first attain their existential being by the way of the dependent origination path [from fabrication (Sankhara) to Being (Bhava),] through the human level. They have to pass through humanhood to attain a beinghood (bhavahood) ; and from that bhavahood, they attain their devahood level.
So it is not that devas are "less" than man (as sometimes heard), but just that they
have to go through manhood to access their level of devahood.
"At last a human rebirth!" means that it is a chance to enter the path to go further up ; it is the chance to access
the realm of the devas.
Later samsaric rebirth will not have to go through the same process ; I guess. They should not "have to" go through the humanhood level.
I suppose that someone who have attain deva's level ; unless he really messes up, should not have to go back through human level once more. Once he enters being level (human,) he just have to dismiss all the previously acquired "khandhas" ; from holding Upadana) to fabrication (Sankhara,) each one in turn - one at a time, without going back. And he should follow the
upanisa path as well. That should allow him to have a rebirth at the level he attains during his life time (although he should never wish for it).
Does that make sense?