The IRS knows:

https://www.irs.gov/newsroom/qualified-charitable-distributions-allow-eligible-ira-owners-up-to-1000...

"They can inform their IRA administrator to make the contribution directly to the charity."

Have to. Not a Can, but a Must.

"Can they consider this amount as their RMD?"

Yes: https://www.irs.gov/newsroom/reminder-to-ira-owners-age-70-and-a-half-or-over-qualified-charitable-d...

"If so, I believe the amount would be excluded from their taxable income."

Yes.

"Can the OCD be considered a charitable contribution, allowing them to itemize?"

No. It would typically be reportable income and then offset by that deduction. A QCD already excludes the distribution from being reported as income. Can't double-dip it.