It seems rather odd to be upset that a television programme might teach one’s children to enunciate properly?

One is genuinely rather confused as to exactly what it is with which you take umbrage.

I've noticed that a lot of my daughters friends put on American accents when they're playing; we're in the UK, so presumably they just watch a lot of american tv. I don't think it's particularly alarming though, I wouldn't think to warn someone to 'be careful' of letting their kids watch My Little Pony because they might imitate the accents

That article makes it out to have a positive effect so I'm not sure what you're trying to be careful about. Perhaps you want your child to say "thank you" and "please" less?

You would be careful because they are watch a show that increases their vocabulary?

haha what’s there to be careful about that? I love that thanks to Peppa Pig we had a little bit of British culture added to our home.

Similarly now with Bluey (Aussie show) and us occasionally saying Brekky for breakfast.