If a unit that has been buffed with the Alacrity (Invoker) is sent to limbo, while holding an Aegis of Immortal or having the skill Reincarnation (Skeleton King), that unit comes back to life without the Alacrity buff.
No issues with actual Death.

Reproduction Steps:
  1. Get an Invoker with Alacrity
  2. Create an allied Skeleton King with Reincarnation
  3. Buff him with the Alacrity, which has the fixed 9 seconds of duration
  4. Kill him somehow
  5. Wait for the Skeleton King to come back to life

Current Result:

Skeleton King resurrects without the Alacrity buff.

Expected Result:

If the Alacrity hasn't expired during the resurrection delay, the Skeleton King should come back to life with the remaining Alacrity effect.

9 seconds of duration of the Alacrity makes this bug slightly important, at least more than the Cold Snap one.
The Alacrity is removed with actual Death, which is alright. On W3 DotA, the Alacrity visual on top of the hero remains even after Death, but the hero is not affected by the Alacrity IAS or the bonus Damage, which is the part we should take into consideration.

Aegis'd death is not the same with a regular death.