Agree with those that reiterate the speed reduction.
If I give a 'level by' or 'speed at' then give another level change before
the initial level is reached, I add 'previous level/speed restriction still applies'.
Similarly if an a/c calls on a 'when ready' to be level by and I reclear it to another level before it's commenced descent I give 'previous level restriction still applies'.
Most if not all my colleagues use the same or words to that effect.
Cheers