Will be visiting the UK next year with a teen. It looks like Bletchley Hall would be an interesting stop, but I see no mention of it in any Fodors publication or in another popular travel source. Any idea why? Is it worth visiting? Our time is limited to spring break, so we have to be selective. Please advise.

I assume you mean Bletchley Park.
We have only visited the computer museum there, since it houses the WITCH computer DH worked at college, plus others we both worked on later. We didn't visit the codebreaking part, but others on the forum have done.
I am not sure I would go out of my way to visit unless it is an absolute must see for you, especially if your time in the UK is short.

Fascinating, but a teen without an interest would be bored.

How data management shortened WW2 would be a good title

Welcome to Fodors. Unfortunately it is impossible to answer your question because we know nothing about the rest of your itinerary/, nor your interests. If you are going to be in that genera Buckinghamshire area, if there is interest in WWII and/or code breaking -- it can be fascinating. It would require a full day if you are coming up from London.

My techie husband and I (history buff) really enjoyed Bletchly Park and the computing museum.
We walked through the buildings to see the recreations of the work and living spaces.
We also took the computing museum guided tour. I was the only female on the tour. Great guide. Best for those truly interested in the development of computer and codebreaking. More indepth than I needed.😏 We have since visited the computer museum in Palo Alto. Bletchly Park was light years better.

We did it as a day trip from London, but not our first trip,