Barring any signings/injuries/trades/cap dumps/waivers etc. I see our D (to start the season) as:
DDK-Green
Nemeth-Hronek
Cholo/Kronner-Bowey
I'm thinking Kronner is 60/40 coming back.
Seider-GR or Mannheim
Kaski-start in GR to get used to NA ice (called up for 9 games or more after TDL)
Daley-LTIR/traded/waived/dumped
Big E-LTIR/traded/waived/dumped
I feel like a Cholowski-Bowey 3rd pairing would be an absolute disaster defensively, which would likely negatively impact their development.
I think your top 4 is pretty realistic, but the 3rd pair probably ends up a rotation of Daley/Ericsson/Bowey, or Daley/Ericsson/Bowey/Kronwall if the latter returns. If they carry 8 for the season, Blashill probably dresses 7 on some nights, with Kronwall getting some sheltered starts and PP time as #7D.
Cholowski's probably at the top of the call up list, and I'm sure they'll find a way to call up Hicketts at some point too. Maybe Kaski and Lindstrom get looks at some point, but they're probably tabbed to spend a year in the AHL unless they really tear it up.
Then at the TDL, they probably look to move two of Green/Daley/Ericsson, or all three if they're getting back another waiver eligible project D like Bowey, which gives them 6 for the last 1/4 of the season and allows them to give multiple D in GR looks using emergency recall.
I doubt even the infallible Steve Yzerman would look to dump off Daley and Ericsson at the start of the year when they could either:
A. Have a decent season and potentially return assets from a contender looking for some experienced D depth near the deadline
B. Have a poor and/or injury filled season, which would allow the team to rotate in or call up young guys
I know it's not completely relatable due to their respective ages, but a year ago there was lots of hope on here that Holland would trade/waive/dump Nick Jensen at the beginning of the season. Instead they hung onto him and ended up turning him and a 5th into a 2nd and Bowey. I doubt Daley or Ericsson bring that kind of return, but they can probably still bring in something as long as they're healthy. At the last deadline, Adam McQuaid missed a chunk of the year with an injury and spent time in the press box with the Rangers but still pulled a 4th and 7th, and a 35YO Ben Lovejoy fetched a 3rd. Hell, Michael Del Zotto barely played for 2 different teams and still fetched a 6th. Draft picks are gold for a rebuild. Might as well try to make some lemonade out of lemons.