I mean, a new Donkey Kong is likely, because it's obviously a well-known and established franchise - but I think Reggie is just giving examples of two big, classic Nintendo IPs that had new titles in the last few years (Donkey Kong Country: Tropical Freeze, Mario vs Donkey Kong: Tipping Stars, Metroid Prime: Federation Force and Metroid: Samus Returns all came out since 2014), so that it's not weird to mention them casually (imagine if Reggie had said "Metroid and F-Zero"... it would be weird, right?) and saying Nintendo constantly tries to make something interesting with them.
Now, if we're talking about hypothetical revamps of the Donkey Kong franchise... I could see Nintendo trying to make it a traditional 90s platformer title, in 3D. That could be fun. We've already had five Donkey Kong Country titles and only one 3D Donkey Kong title, so I could see them giving it a try.