Are "newly created positions" meant to be advertised?

[MakeTeaNotWar]

Our manager sent an email around the team today offering congratulations to a teammate who had been appointed to a newly created position which is in effect, a promotion within the team. This has put people's noses out of joint as nobody else was given opportunity to apply. Should the role have been advertised?

I dont think there's any requirement, no

Only if there is an internal policy saying so-there's no legal requirement to advertise. Although for the very reasons you mention, it's completely daft not to at least advertise internally as all it does it put people's backs up.