The theme of the division of labour in Threads would be even more pronounced now. In a more technological age, the people at the top are often very good at one thing but know nothing about other things. Someone who is a jack of all trades but a master of none is more likely to be unemployed nowadays, so there's an incentive to specialise. (This is what I understand to be the "threads" that make society vulnerable.)
I was thinking that, if this were set in London [or many other cities] now, the film would be very different, especially at the start. 90% of Londoners never speak to their neighbours. I wonder how a community where no one knows one another would cope during a nuclear attack.
I have lived in Sheffield as well as London. For some reason, Sheffield has a relatively strong sense of community for a city of half a million people.

I think The Day After also suffered from the threat of network interference. It was hard hitting and shocking but it could have been even bleaker. Sadly U.S television has to deal with something British television doesn't and that is pressure from networks and advertisers pulling out.
Ted Turner aired Threads on his network out of his own pockets because no advertisers would go near it.

a remake wouldn't help, The Day After had a similar theme but only highlighted what happens when good ideas fall into the hands of inferior talent.

it looks nothing like the 1960's?
How did you come to that conclusion?
It may well be dated in many ways but any film that wants to capture the spirit of those times is designed
to date
. Not only is that part of it's charm but it's important because it puts it in it's natural historic narrative.
1984 was actually a long time ago now.