Afraid that I don't know the first thing about what sprockets that Haibike run on their bikes, but odd peculiarities in fit have cropped up lately, especially with bikes from Giant.
You can certainly buy 16t sprockets that aren't raised, and by raised I assume that you are meaning the e bike specific SRAM sprocket which has one regular flat sided tooth, followed by one raised sided tooth.
I use Connex sprockets as I have found them to be the most durable, and whilst being flat sided, I was assured by directly by Connex that they are compatible with both Shimano and SRAM. I run a Shimano XT set up on one bike and an SRAM X1 set up on the other, and both use the same Connex sprocket. I am also now due to take delivery of a 2017 KTM which uses an SRAM EX1 set up, which does use a raised sided sprocket from OE, and only time will tell if I can use a flat sided sprocket on that.
If you do opt to buy a Connex, I tend to use Pro Gorilla from Germany, but I buy several sprockets at a time. I think that 16t Connex sprockets can also be found on Ebay UK.
To eliminate doubt, you could ask on either of these two places.
http://www.pedelecs.co.uk/forum/forums/electric-mountain-bikes-emtbs.47/
https://www.facebook.com/groups/313908402329634/ (UK legal bikes only)