I find the arguments presented here insufficient to warrant the conclusion.
First, the argument that “In order to experience Heaven, it is necessary to have an intellect and reason.” is faulty for a number of reasons. Logically, the only argument given for this conclusion is that of Aristotelian Forms. There is a lot of work out there expressing this but one readers here might find interesting is a paper written by David Banach of St. Anselm College,
What Killed Substantial Form, @
anselmphilosophy.com/substance/. (note this is but one of dozens of papers showing weaknesses and faults in Forms). Since Forms are a false argument ontologically speaking, it is not valid.
Second, even if the Aristotelian Forms is a valid argument, I see no reason how the idea of Forms as Aristotle developed it can logically exclude animals et al from having an immortal soul. I think the argument presented is not sufficient to warrant the conclusion. Jesus was aware of even small birds, that must mean he must have some intellectual interaction with them. And if he says he has an intellectual interaction with ‘even sparrows’ who are we to say they do not have sufficient intellect to have an immortal soul.
I am not saying they do, but…I am pointing out a weakness in the argument, specifically it is anthropocentric.