The OS X release cycle back then was much slower. It was 4 and a half years between when Apple shipped the first Intel PCs and Snow Leppard was launched. Even then, Apple continued supporting and updating Leppard for a couple years after that. Even if you bought a PPC Mac on the last possible day, you still got 5-6 years out of the machine with security updates.
Seems to me like we'll see at least comparable support for Intel Macs going forward. Particularly since they will still be shipping Intel Macs for at least another year, possibly another 2 years.
While the risks are probably less than they were earlier in Apple's history, I'd much rather take a chance on a first-generation Apple Silicon SoC than on a first-generation MacBook Pro redesign.
A laptop that satisfy my long battery life ultrabook experience AND capable to run steam games without compensating on performance.
Though the 13" air is not in the same target user group vs. the 15" pro, so you might not find the same excitement as I did.
I don't ever recall regretting something I've purchased, say, more than 1 month ago. The act of purchase is foregone past by that point.
I expect the v1 tax this time around is that the externals are exactly the same as the Intel machines. Compared to what laptops like the Dell XPS 13 are doing with larger screens in smaller bodies, the current Air and 13" Pro designs are getting a bit long in the tooth now.
I expect next year we'll see new design for the iMac with the M1X, or whatever the bigger variant will be called, as the current version is absolute dinosaur at this point, but I also think we'll see an updated design for the Air and 13" Pro (maybe 14" like how the 15" went to 16"—it would certainly help differentiate the Air and Pro a little more).
My dream laptop would be an iPad Pro 12.9 with a Magic Keyboard and M1 chip which could run both full screen iOS apps and full Mac OSX. In a perfect world it would have an extra USB-C port too.
But to be honest, just a regular macbook with a touchscreen would be great now. I've had enough of people trying to use my Macbook at work, prodding the screen to try and scroll down, then trying and failing to do the two finger scroll gesture on the touchpad.
I think there are more devs invested in the macOS ecosystem with hardware during this transition than the last, so it would make sense for Apple to let those Intel hold outs still keep up with the latest macOS version.
I would say two or three cycles of macOS upgrades before they EOL Intel support.
If the reports are to be believed on performance and Rosetta than this upgrade may be one of the smoothest in Apple history. The Intel CPU has had an incredibly long run, 15 years, at Apple. If they are confident they can make the leap and not leave their users in the lurch more power to them.
I'm still on the fence on buying an M1 laptop. Apple users know you pay an Apple tax and a v1 tax. My MBP is getting so long in the tooth I may have to ignore my own advice of not getting first generation Apple hardware.