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.

@@ -20,0 +21,2 @@
+<xref type="see" seq="1080510">テレビ・1</xref>
+<s_inf>occ. said テレビ</s_inf>

again:
https://kotobank.jp/word/どーす�%8
2%8B%21%3FTV%E3%82%BF%E3%83%83%E3%82%AF%E3%83%AB-1717561
（TVタックル）
_
"通称はサンテレビ（SUN-TV）"
https://ja.wikipedia.org/wiki/サンテ
%E3%83%AC%E3%83%93%E3%82%B8%E3%83%A7%E3%83%B3
_
https://ja.wikipedia.org/wiki/TVジョ�%
83%E3%82%AD%E3%83%BC
『TVジョッキー』（テレビジョッキー）
_
"テレビをTVと略すことはあっても「薄型ティーヴィー」とは言わんだ
ろ"
https://twitter.com/DimWryon/status/894785532479197185
_
テレビ番組 7.8m googits
ティーヴィー番組 58
TV番組 9.7m (not properly parsed because of the romaji 
but lots of real hits)
http://www.mag2.com/p/news/264014
「民放のTV番組は無料じゃない」と気づかぬ人がお金を失う理由
_
I showed the text "TV番組" to a native speaker and asked 
how they'd read it and they said テレビばんぐみ.

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〕
_
"NASA" is never read as "N, A, S, A" but always as 
"Nasa". Then there's scuba, laser...
_
Some pronounce "SQL" as "sequel" 
http://patorjk.com/blog/2012/01/26/pronouncing-sql-s-q-l-
or-sequel/
_
Is it a *reading*? If it's the way it's read, I'd say 
yes.
_
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.

GG5, WWW hits for ティーヴィー

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.

@@ -9,0 +10,9 @@
+<r_ele>
+<reb>ティーヴィー</reb>
+</r_ele>
+<r_ele>
+<reb>ティー・ブイ</reb>
+</r_ele>
+<r_ele>
+<reb>ティー・ヴィー</reb>
+</r_ele>

http://yomikata.org/word/tv
6 votes (50% of the total) for reading TV as "テレビ" vs 
4 points (33%) for "ティーヴィー"
https://ja.wikipedia.org/wiki/ビー�%8
8%E3%81%9F%E3%81%91%E3%81%97%E3%81%AETV%E3%82%BF%E3%83%8
3%E3%82%AF%E3%83%AB
『ビートたけしのTVタックル』（ビートたけしのテレビタックル）

I think we should merge in テレビ here.

koj, daij, gg5