Why is Win 10 not offered on early Yoga?

[Davidhs]

A friend has an early Yoga - that I bought for her. It now runs Win 8.1 and we keep it up to date with both Lenovo and Windows updates.
Rather to my surprise Win 10 has never been offered on this system. Is there some reason for this?

By contrast my 4 year old TP W520 was offered Win 10 months ago and has been running it happily ever since.

[ZaZ]

This may be of interest.

[Davidhs]

Thank you, Zaz.
I will check the KB items listed in that reference on her Yoga - it may be next week before I am able to look at it.

[Rob]

I manually installed Win10 on my first-gen TP Yoga. I haven't had any issues running it with Win10. It might be worth just going in and performing the upgrade manually - especially with the free Win10 upgrade ending in July.