[Gimp-developer] Behavior change in paint modes between 2.8 and 2.10

[Ofnuts <ofnuts gmx com>]

In 2.8, on a transparent layer, paint something blue, set the FG color 
to red, set the paint tool to "Hue" mode, paint over: the blue parts 
turns to red, the transparent parts remains unchanged.

In 2.10, if you do the same thing with the non-legacy modes, the 
transparent parts are painted. The legacy modes behave as in 2.8, and it 
seems that setting the alpha-lock also provides the 2.8 behavior.

It used to be that painting a layer with the paint tool in mode XXX 
would give the same result as adding a transparent layer in mode XXX and 
painting on it in "Normal" mode.

Is it a bug/regression or is it a deliberate change, and if the latter, 
what is the rationale?