What is that reduce the number of transactions? you can't stop people from transacting, segwit does it by reducing the size of the data included in each block. who opens channels in LN?
Probably he is talking about the reduced of unconfirmed transaction once SegWit is implemented. I believe that is the purpose of Segwit, to establish the fix for bitcoin scalability if I am not mistaken. It gives way to Lightning Network that will greatly help in the transaction.
The purpose of SegWit to fixed the malleability problem of bitcoin and to increase the blocksize is not the main reason to implement SegWit.
The lightning network as an off-chain solution for bitcoin to make the transaction will be faster.
Without SegWit, LN just will less on his benefits.
I mean SegWit is not to solve the scalability problem.