Italic mu in squared Latin abbreviations?

[Ivan Panchenko via Unicode]

Is there a reason why the mu does not appear upright in the reference 
glyph for U+3382 ㎂, U+338C ㎌, U+338D ㎍, U+3395 ㎕, U+339B ㎛, U+33B2 ㎲, 
U+33B6 ㎶ and U+33BC ㎼ of the CJK Compatibility code chart? I also see it 
this way in fonts such as Junicode, Unifont and WenQuanYi Zen Hei while 
U+00B5 µ is displayed upright there. “Prefix symbols are printed in 
roman (upright) type, as are unit symbols, regardless of the type used 
in the surrounding text, […].” (SI Brochure)

By the way, U+3396 ㎖ is displayed with a capital M instead of a small m 
in Droid Sans Fallback (as included in my Ubuntu system) and Arial 
Unicode MS, suggesting “megaliter” instead of “milliliter”! The latter 
font has not been developed further since version 1.01, does someone 
know about the former? Droid fonts can be purchased at fonts.com but I 
cannot find the fallback font there (so maybe contacting Ascender would 
be of no use).

Best regards
Ivan