Deadline guarantees on addstream event / update set of remote streams

I would expect to be able to find a guarantee on the spec that all
addstream events get queued before the successCallback of a
setRemoteDescription or some other well defined deadline (e.g. signalling
state becomes stable). But after reading it I just got more questions:

Question 1:
"""Onnaddstream happens as early as possible after the
setRemoteDescription.""" - this "as early as possible" sounds vague. Can
anyone explain me what to derive from this sentence?

Question 2:
Can anyone breakdown these 2 quotes? It is unclear for me on how they
interact with each other.
a - """"""This will be fired only as a result of setRemoteDescription ...
This callback does not wait for a given media stream to be accepted or
rejected via SDP negotiation."""
b - """The creation of new incoming MediaStreams may be triggered either by
SDP negotiation or by the receipt of media on a given flow."""