I disagree with the "voluntarily" part unless it was volunteer to go or get hanged for being a rebel. I can also sense the bias there. He was right about a lot of the Irish being indentured servants (which was quite bad - but wasn't always permanent and doesn't extend the punishment to the kids) with a few (not many) of them being owners.
I think the author was very obviously trying to draw a very distinct line between the Irish and the black experience. Which is for the most part appropriate, but back during the 1600s I’m not sure there was all that much difference.
As you say, the Irish in the 1600s were to a considerable extent shipped off as rebels and convicts. I’m not sure there was a great deal of attention given to whether their indentures were in proper order and they were released at the end of them.
It is also well-known that many Irish, Scots and English were kidnapped and sold as indentures in America or the Caribbean. The basis of R.L. Stephenson’s Kidnapped, which I read 50-some years ago and still remember pretty clearly.
The author conflates Irish experience from early 1600s to mid-800s as if it was all one thing.
Also noticed he seemed to ignore the elephant in the room. Who is Irish? The BIG Irish immigration to America in the 18th, absolutely enormous, was among Protestant Irish, what Americans call Scotch-Irish. Many of today’s professional Irishmen don’t consider them to be really Irish at all.
Of the various groups and peoples he discusses, were they Scotch-Irish or Irish-Irish?