That spiel from Scotrail hasn't changed in a long time. Unfortunately it hasn't been true for at least 15 years, maybe more. The one time direct bus from Armadale to the Kyle of Lochalsh and beyond was stopped (at one time it went as far as Strathcarron via Plockton on the mainland).
Now you have to change at Broadford. Even in the summer, when there are more buses between Armadale and Broadford, and between Broadford and Kyle the timetables don't really meld to get you to the Kyle in time for the last train.
The first train from Glasgow at 0822 gets you to Mallaig at 1340 and the last train from Kyle at 1713 gets you to Inverness at 1959.
The ferry leaves at between 1350 and 1445 (depending on the day of the week)- https://assets.calmac.co.uk/media/tsldrcfn/stt-18-mallaig-armadale-2.pdf for the 45 minute crossing.
There is a bus at 1532 from Broadford, arrives Uig at 1551.
The other option is to get the 1710 bus from Armadale, arrives Broadford 1737, then the Citylink bus from Broadford at 1825, arrives Inverness at 2058. After the Kyle of Lochalsh it doesn't follow the railway line, but tracks south eventually picking up Loch Ness- so a taster of what you will see by water eventually.
So you would need to have a pre-booked taxi between Armadale and Kyle.
You could alternatively take that train to Mallaig, time in Mallaig then the 1530 Shiels Bus back to Mallaig, arrive 1710, then either Citylink or Ember Bus from Fort William to Inverness.
Next day, before the cruise embarks you could take the 0900 train to Kyle of Lochalsh (35 minutes there) then back to Inverness, arrive 1442.
Chances are your cruise will have time in Fort William (normally berth at either the top of Neptune's Staircase, for Banavie station) or Corpach (for Corpach station) probably giving you the time to do the Mallaig Extension Railway that day.
If so there is another way from Fort William to Inverness on 4 July through wonderful scenery (Glencoe then Lochearnhead)- the #913 bus at 1610 from Fort William to Perth (for train or bus to Inverness).
On 6 July the cruise ship 'Lord of the Glens' sails the other way than you are from Kyle to Inverness with shore excursions to Eilean Donan, Armadale Castle, Inverie, Tobermory, Iona (from Craignure) and Glenfinnan. Those Caledonian Canal cruises on the small cruise ships are magnificent. Enjoy.