Will we ever be able to add our alts on same account to each other's Friend List?

[LineageRazor]

Will we ever be able to add our alts on same account to each other's Friend List?

Unlikely to happen, for pretty much exactly the reasons you WANT it to happen. SE wants everyone's inventory to be limited they way that it is limited. They don't want players to have mule characters, who exist to be extra storage space.

Any chance they might have changed their minds on this disappeared when they introduced the extra paid-for retainers. Now, if you want additional inventory, pay up.

Folks argue that you CAN use your alts as mules already, but it's awkward. That's exactly right: it's awkward, and that's just what SE wants, so that players will consider non-awkward ways to get extra space (e.g., buy their retainers).

It's not nice. It's not fair. But it's the way things are. Time to open up that wallet! Or, just get better at keeping your inventory clean of clutter...

[XiXiQ]

Any chance they might have changed their minds on this disappeared when they introduced the extra paid-for retainers

alts don't get access to the other retainers. If they are so concerned about the retainer income, they can make it if you have all 6 extra, you get your alts added to your friend list automatically. Then it's a selling point.
It's certainly nothing to do with RMT if it happens under the same account.