The agenda here was not to pursue some sinister 'pro' gay agenda but to combat homophobic bullying. How well the material actually succeeded, or how inappropriate it may have in fact been, I can't comment on as (just like you) I haven't seen it. However, the simple fact is that 'playground' education on any subject sex related - in the UK at least - is years in advance of 'classroom' education. If you don't get the message across when they are young it will be too late to shift the attitudes already there. The message here is that it is wrong to bully or abuse gay people (or in the case of kids people including other kids they think might be gay, which is NOT always the same thing), not to 'promote' homosexuality.
why is it not OK to bully or abuse gay people for being gay?