No BlockStream employees have commit/merge writes.

I’m not sure where you get your information from, but even the first wiki search will reveal to you:

Blockstream hired Rusty Russell, a well-known developer famous for his work on Linux kernel, to develop an implementation of the Bitcoin Lightning Network (LN). Russell has a four-part LN explanation on his blog.[9] The Lightning network proposes to reduce transaction costs by allowing nodes to hold some transaction data in the cache before submitting it to the chain.[20]
In May 2016, announced Thunder, which claims to be an implementation of Lightning.[21]
In May 2017, Segregated Witness activated on Litecoin, enabling the Lightning Network to be used.[22] In May 2017 Christian Decker of Blockstream sent the first microtransaction using lightning on Litecoin.[23]

Blockstream not only effectively controls core, they also control the roadmap.