Why was L2/25-061 provisionally assigned?

[piotrunio-2...@wp.pl via Unicode]

In  www.unicode.org Submitting Character Proposals (unicode.org)  it says " 
Often a proposed character can be expressed as a sequence of one or more 
existing Unicode characters. Encoding the proposed character would be a 
duplicate representation, and is thus not suitable for encoding. (In any event, 
the proposed character would disappear when normalized.) For example, a 
g-umlaut character is not suitable for encoding, since it can already be 
expressed with the sequence <g, combining diaeresis>.".   I really 
don't get why L2/25-061 would be provisionally assigned to U+208F when it 
can be composed with combining characters (ˈ̩ U+02C8 U+0329) or (ˌ̍ U+02CC 
U+030D) which should be equivalent to the proposed character, and the potential 
use of the existing combining characters is not mentioned in the proposal, but 
the proposal owner was informed of the compositions before the  Recommendations 
to UTC #183 were made .