Most likely true but his age shouldn't be a talking point, considering Rohit is also touching the same line.
IMO, you can keep Pujara aside in other tours but he excels in the Aussie conditions because of his grit and willingness to take as much as body blow. You need at least 1 guy with this mindset in your team and if I recollect my memories of last decade then only Pujara fits the bill. Elgar comes second best but they didn't tour as much as India.
I would've liked if the likes of Pujara and Rahane offered their services to weaker state boards and scored against big teams in the domestic.
Rohit is the captain of the Indian national team across all the formats, so age is irrelevant as far as he is concerned. Probably the selectors don't want a test squad where half of the guys are above 35. Virat Kohli, Ravindra Jadeja, Mohammed Shami and Ravichandran Ashwin all fall in this category. But I agree with you on his performance in Australia. He has performed exceptionally well in past tours. Not so sure about Rahane though. I haven't heard about him in a while. He played a few matches for Mumbai in Vijay Hazare Trophy, but couldn't make a lot of runs.