Harbinger currencies in Standard

Hello,

I know that most of 'new' currencies from Harbinger league will not be implemented in the core game, but I did not read anything about existing currency.

After the merging of softcore Harbinger into Standard, I have now some Harbinger's Orbs and some Orbs of Horizons in Standard which I would like to apply to my old maps.

If I try to apply one of these orbs to a pre 3.1.0 map however, I get
"Failed to apply item: item cannot apply to the target item".

Is this an intended behaviour? Is it still possible to reforge maps in Standard? Or are those orbs worthless now?
Or maybe the issue is just caused by pre 3.1.0 maps and the orbs work only with last maps?

Thank you in advance for you kind answers!