Hi and welcome!
It's not a new thing. I had an IVF 5 years ago with the Olive Doctors (they were at Genesis then, they've broken off to form Olive since) and they were doing eSET's then. eSET is Elective Single Embryo Transfer. And yes, it's to minimize the chance of multiples because of increased risk.
They will assess your chance of success based on the number of embryos transferred during your IVF. If you have a good chance of success they will only transfer 1 embryo. Your case looks to be male factor so you are a perfect candidate for eSET. If they know they've got 1 really good quality embryo/blastocyst, and there is no female factor involved in your diagnosis, then the chances of your partner conceiving with IVF are really good. If there was a female factor, or if your partner was older (35+), or if they cannot get a really high quality embryo/blastocyst, they may transfer 2 because the odds of success would be lower so there is less risk that 2 will turn into a high risk pregnancy (ie multiples).
So if both you and your partner are young and there is no female factor diagnosis, then yes, Olive will only transfer 1 embryo/blastocyst. So will all the other Vancouver clinics, that's not just an Olive thing. You will get the same information at Genesis or PCRM.
It's a good thing. Lots of people want twins and when you're going through IVF it's easy to think that if you get twins that you only have to do IVF once, but the risks of a pregnancy with multiples are real, so the eSET is worth it if you're lucky enough to be in that situation.