Just upgraded my speakers - do I still need the subs

Ref. 1 meta, rated 45Hz – 35kHz (-3dB), still needs sub.

I’m guessing that you will need to get a faster subwoofer. Like the Reference 8b https://us.kef.com/products/reference-8b-subwoofer. 
Another option is a Rel Acoustics subwoofer. https://rel.net/products/s-550?variant=50859609587928
nice 😊 come up on the speakers 🔊! Both options allow you to get a line arrays six-pack. Here is an article about this. https://rel.net/blogs/learn-and-explore/rel-six-packs#:~:text=A%20REL%206%2Dpack%20is%20a%20line%20array,A%20three%2Ddimensional%20soundstage%20*%20Epic%20ultra%2Dlow%20bass

Every speaker is improved by the addition of subwoofers.  I recommend two or multiples of two if stacked.

faster subwoofer? seriously?

for 9 grand? On what planet?

yes the subs are needed for best performance - just need to retune for correct x-over and level for the new mains