I have the feeling that the "legendary thinkpad serviceability" means two things: the document that you cite is publicly available and that customer disassembling the whole thing and replacing one subassembly is supported way of solving warranty claims.
And by the way, the "good thinkpad" series (ie. letter + two numbers) were both made and designed by Acer/Wistron and significantly mechanically simpler than the previous IBM designed thinkpads (eg. if you disassemble "low-cost" 600E, you end up with ~10 random-ish machined aluminium brackets and how to disassemble the thing is highly non-obvious).
For most business line notebooks the maintenance guide is publicly available and you don't have to remove the speakers and lcd screen to access the fan assembly (serious, wtf?). Thinkpad serviceability is overrated, it's certainly not "legendary", even if you can consider it decent.
And by the way, the "good thinkpad" series (ie. letter + two numbers) were both made and designed by Acer/Wistron and significantly mechanically simpler than the previous IBM designed thinkpads (eg. if you disassemble "low-cost" 600E, you end up with ~10 random-ish machined aluminium brackets and how to disassemble the thing is highly non-obvious).