The concept of a Pan-Iran is hard to grasp for non-Iranians.
Most Iranians in Iran are multi-ethnic, and alot have family in different parts of Iranzamin, most Iranians love Iranzamin and most of Iranzamin loves Iran. From Azarbaijan to Tajikistan Pan-Iranism exists, it's very possible Talyshistan would be able to join with Iran when the Islamic Republic is terminated... if that happens some day which I hope.
The bond between people of Iranzamin is not only linguistic, but racial, and most importantly cultural.
Oh trust me, I have been around a fair amount of 'Greater Iran' enthusiasts online over the last 4 years to realise that its pure nostalgia that tends to glorify the Persian empires of old and want to see a new empire/super-state be re-established on racial, linguistic, and cultural grounds. Some advocate usage of warfare to over throw what they deem as 'Arabparasts and traitors' of countries that border Iran to 'save and unite all the Iranian people'.
That being said, nothing wrong with having greater cultural cooperation, understanding, and between neighbours of the region. Nothing wrong with join collaborations in such fields etc.
But to assume that all Tajiks, Afghans, Azeris, Georgians, Armenians, Kurds, Balochis, etc (one who are considered 'Iranian') are desperately dreaming of a Pan-Iranist paradise to take place is just laughable.
And as I said, this 'movement' is essentially a favourite past time of the younger Iranian diaspora whose parents originate from Tehran, Isfahan, Shiraz and but now live in places like LA (Tehrangeles), Toronto (Tehranto), Germany, UK, Australia etc just to have a sense of belonging and justify their nationalistic pride with their farvahar necklaces and shirts, and going "do do do do do do IRAN!" in football matches, and then saying "Oh we are Persian!" with a face when they are innocently mistaken to be 'Arab' by others.
Its cute, but also laughable.