Are Their any Tube Preamp with Home Theater Bypass?

Yes, it is true that the tubes in a preamp will be “consumed” even when using HT bypass. Just keep in mind signal tubes in a tube preamp last longer than power tubes in a tube amp. 12AX7’s, for example, can last upwards of 10,000 hours. I’m about 75% 2-channel music, 25% multi-channel HT, so not a huge concern for me. If you’re the reverse, it might be more of a concern, but not nearly as much with a tube preamp as if you were looking at a tube amp with a bunch of KT88’s that you were going to be running 8 hours a day between music and HT. It was for that very reason that I went with a tube preamp and solid state power amp.

If the tube preamp has a true bypass, then it does not need to be powered on, and passes the HT signal through it.

As you already mentioned, 10000 hours is a quite while and should not pose a concern, even if the preamp doesn’t have a bypass… it is 1-10 cents/hour for a preamp’s tube cost.

I am looking at this issue as well and found this helpful page listing both integrateds and preamps with HT-bypass:

It is updated but not complete (for instance it is missing Modwright).  I have considered moving my Schiit Freya plus to my AVR system, which does not have HT bypass but does have a passive mode.  Some problems I see with just using unity gain are 1) the fear of switching inputs without lowering volume, and 2) I believe that you cannot utilize an unbalanced input (from an AVR for instance) going to a balanced output to your amps in passive mode.  I could be wrong on this second point.

I have a related question.  If you want to incorporate a single subwoofer into both the HT system and 2 channel system, how do you accomplish that?  Do you simply have to use two different inputs into the sub?

Cary Audio SLP-05.  End game preamp. Has HT bypass. 

The TAD 150 Signature has it, if you can find one ( used only).  It’s passive, so the pre doesn’t need to be powered up.

Yes I have a McIntosh MX120 home theater preamp, with a McIntosh C2300 tube preamp. The C2300 has goes into bypass when the MX130 is on watching TV. Works excellent and love them both. Highly recommended. Although the C2300 has updated versions C2600 they all have bypass.