So long after I created this thread.
I was thinking on this. It is said that Akshobhya sutra is one of the first dealing with Pure Land doctrine. The Trikaya doctrine wasn't, perhaps, fully developed already.
Also I read this from Paul Williams:
"According to such texts as the Dazhidulun, the Lotus SEtra (text, rather than its East Asian
interpretation) and the Suvarnabhasottama Sutra, after an enormously long period of time a
Buddha will eventually enter ﬁnal nirvaua, although according to the ﬁrst of these the Buddha’s
Transformation Bodies will continue in order to help sentient beings. These texts clearly
operate with the (older?) notion that the length of a Buddha’s life, as with all beings, is
the result of his merit gained in the past. Since the Buddha’s merit, while immense, cannot
be literally inﬁnite (as it is the result of ﬁnite acts), the Buddha’s lifespan must in reality be
ﬁnite (cf. Suvarnabhasottama Sutra 1970: 5–8). In other texts, however, apparently later in
date, such as the Buddhabhumi Sastra, the Buddhas never enter ﬁnal nirvana. Part of the
problem is that some texts view beings as inﬁnite, and other (Yogacara) texts maintain that
there are some beings who as a matter of fact will never attain enlightenment. The Buddhas
remain, therefore, either to continue to save inﬁnite sentient beings, or to try and provide
more pleasant rebirths for those who will never put an end to the round of samsara. Here
we ﬁnd the extreme point of the Mahayana emphasis on compassion. The concern of the Buddhas is so
great that they are resolved never to enter any ﬁnal nirvana of complete quiescence and peace, but
rather to remain and help other beings."
(Mahayana Buddhism, page 186)
Also, in the beginning of the Pure Land doctrines, it was believed that Pure Lands did have an end, they were modeled using our world as reference, like if Pure Lands were another far far distant galaxy or world. So perhaps, the Sutra were writen with was believed in that time about Pure Lands, with what people knew that time.
Also I can think on this, it is said that Amitabha True Pure Land is Nirvana itself, and that the Transformation Land is for those who didn't entrust fully to Amitabha. It is described that Transformation Land is not limitless, that people there cannot hear Amitabha, the physical descriptions it is said to belong there. If we use the same reasoning, we can say that the "Dharma Ending Age" in Akshobya Abhirati Pure Land, is just an illusion and not the True Pure Land. At the end, the True Pure Land is not different from Nirvana, from enlightenment itself.
What I still find hard to believe is in an objective, traceable on a map Pure Lands. I can believe, and try to interpret in that way, Pure Lands as in different, subtle and transcending planes, but I'm still not sure.