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NASA is a bit of a red herring. The Japanese say ジス for ＪＩＳ and ジャスダック for ＪＡＳＤＡＱ. 
I think what we're seeing here is a sort of 義訓. People see TV and think テレビ, but like Rene I think it's too much to call テレビ a reading. I can accept 田舎 being read いなか, and (worse) 啄木鳥 being read けら, but merging テレビ into ＴＶ/ティーブイ it's a step too far.
How about a two-way xref with notes? I'll set one up here, and it can be used with ＯＰ if accepted.

Abbreviations aren't always read exactly as they're 
written. Consider "etc."　- if we used this spelling as a 
headword, wouldn't it make sense to add エトセトラ as a 
reading? 
daijr actually does
エトセトラ【et cetera】
以下に列挙すべき語を省略する場合に用いる。…等々。…など。その他
いろいろ。 〔etc.; ＆c. とも書く〕
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"NASA" is never read as "N, A, S, A" but always as 
"Nasa". Then there's scuba, laser...
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Some pronounce "SQL" as "sequel" 
http://patorjk.com/blog/2012/01/26/pronouncing-sql-s-q-l-
or-sequel/
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Is it a *reading*? If it's the way it's read, I'd say 
yes.
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Merging is maybe a little extreme since no other 
dictionary does this, I don't know, but I think there's 
at least a case for adding a note.

テレビ can't be merged in IMO.  surely a native speaker would agree that テレビ is not a *reading* of ＴＶ.

I think we need to think seriously about the issue of "readings" for acronyms/initials which are really meanings.
ティーヴィー also seems to be matching TB.

I think we should merge in テレビ here.