New Sternguard to replace the old Space Marines?

Picture of new plastic Sternguard have surfaced in the last week, with no action being taken by GW? The question on my mind is what is going to happen to the old models. Should we be ordering as many as we think we will needs now, or will they continue to be offered on direct order only. I’m not sure I want to take the risk.

The old Sternguard

The New Sternguard

New space marine sternguard sergeant

Sergeant in Mk8 Power armour with Plasma pistol and power sword

New space marine Sternguard with bolter

Sternguard with bolter

New space marine sternguard combi gravgun

Sternguard with combi gravgun

New Space Marine Sternguard combi melta

Sternguard combi melta

New Space Marine Sternguard Heavy Flamer

Sternguard Heavy Flamer