The article's only piece of evidence is the anagram, which strikes me as interesting but not conclusive.
Rather than M being Silva's real mother, I think a key element of the story is that Silva and Bond had virtually identical past relationships with M: both Silva and Bond had been orphaned or abandoned as children, leading to each of them being selected by M to be developed into secret agents.
The adult Silva is enraged by the realization that M had taken advantage of his vulnerable background and turned him into a killer, as he explains to Bond via the anecdote about the two rats:
[The rats] start eating each other until there are only two left. The two survivors... Now, they only eat rat. You have changed their nature. The two survivors. This is what she made us.
The movie shows the adult Bond experiencing the same resentment toward M (for example, when asked what word he associates with "murder," Bond says "employment"). But the movie also shows the difference between Bond and Silva: Silva's anger at M leads to his doom, but Bond is able to see the good in M, to forgive her, and to move on with his life. The ultimate proof is how Bond does his best to save M, and then even after she is killed, he is able to return to his job with a renewed passion for it:
[Skyfall's closing lines]
Gareth Mallory (the new M): So, 007... Lot's to be done. Are you ready
to get back to work?
James Bond: With pleasure, M. With pleasure.