Will we ever see another update for KSP 1?

[RUD Everyday]

Very soon, a year will have passed since the last update of KSP 1, and as time goes on, eventually the software of KSP 1 will break on be rendered unusable.

[Vanamonde]

It's unlikely. The team has moved over to working on KSP2. 

[Nazalassa]

18 hours ago, Vanamonde said:

It's unlikely. The team has moved over to working on KSP2. 

That's the point: if they've moved to working on KSP2, no one will work on KSP¹ and it will suffer what is commonly called 'software rot' - that is, KSP¹ will rely on libraries that will get older and older as time passes (on the (very) long term - thx), eventually getting deprecated and unavailable (the libraries, not KSP¹), and no one will update KSP¹ to use new versions of these libraries. Chances are high that in some time KSP¹ won't be able to run at all, except on VMs.
Unless someone can update it - ...

Edited January 3 by Nazalassa

[RayneCloud]

There is a long life left ahead for KSP 1. A long, and happy left before the rot you talk about hits. Tho, I have some small measure of faith that if it needed it, that IG would put out some sort of 1.12.6+ update to maintain KSP 1 and keep it from dying out entirely.

[HebaruSan]

Version 1.5.1 came out on 2018-10-17 and is still available in the "Beta" list on Steam. Anyone with concerns about this software "rotting" can try that out and see whether anything has broken yet after six years.

38 minutes ago, Nazalassa said:

KSP¹ will rely on libraries that will get older and older as time passes, eventually getting deprecated and unavailable (the libraries, not KSP¹), and no one will update KSP¹ to use new versions of these libraries. Chances are high that in some time KSP¹ won't be able to run at all, except on VMs.

The chances of that are low, not high. The libraries are bundled with the game itself (go take a look in the KSP_x64_Data\Managed folder) so they're not going to become unavailable. You'd have to wait for incompatibilities with the OS itself to crop up, which OS vendors try to avoid.