That headline is rather misleading. The key quote is:

"Under the new rules, heterosexual single men and women and gay men and women who want to have children will now be given the same priority as a couple seeking IVF because of medical fertility problems. "

I am quite happy that the WHO is taking that stance to support the human rights of non heterosexual couples.

I feel like the people who are jumping all over the use of the term 'disability' are doing so disingenuously rather than standing up and saying that they believe heterosexual couples are inherently more worthy of having children.