Can we just make it so that when we select brush presets on creating bundle, the texture and tip that it’s referencing is automatically included in the exported bundle?
And it doesn’t have to do it for every presets, it can just be an option that you can tick for individual brush presets. Such as :
“
auto-include tip and texture for this preset”
That is already the case, at least for the brush-tips, for patterns/textures I haven’t tested it so far.
Michelist
Care to explain how it’s already the case for brush tips? The tips don’t seem auto-included with brush presets in 5.0.
If you have presets that have brush tips associated with them, then when you create a bundle, all you have to do is add those presets to the bundle, Krita will take care of the associated brush tips itself without any outside intervention and include them “automagically”. 
This was an accidental discovery of mine that I first reported on here:
According to @tiar, this is what she intended when she created the new resource management.
I have not yet checked whether the automatic takeover also applies to textures, since there are no error messages for textures when they are added to a bundle whose presets use those textures. I think to remember that the textures have to be added even if a preset refers to them, but I would like to encourage you to try out if the textures might be added automatically even if you do NOT add them to the bundle during bundle creation.
As I said, it was a random discovery with the presets with brush tips that cause error messages when the associated brush tips are added during bundle creation in the Resource Manager - I didn’t worry about the textures that times.
Michelist
The job seems to work only when the .kpp brush preset is made in 5.0 , which might be one of the reasons why the brush presets created from 5.0 cannot be read in 4.x 
A simple answer would be: No and YO (Yes/No).
More detailed is that I noticed it when I created bundles in Krita 5 from brush sets created for Krita 4 by @IForce73 and @fizzyflower. Krita 5 recognizes the dependencies of presets created in Krita 4 as far as the dependencies are brush tips and will include them into the bundles you create with them, as written before I would have to test this for the textures in detail, but I think their dependencies are not recognized. These dependencies were only noticed (or recognized) because Krita 5 gave error messages when adding brush tips during bundle creation that are needed by the presets added in the bundle, these error messages never existed for the textures used by presets, so I believe that this dependency is not checked, but would have to test it to make a valid statement.
Presets created in Krita 5 that don’t work in Krita 4 include only 2 categories as far as I know, firstly MyPaint presets and secondly presets with brush tips. First because Krita 4 lacks the engine for this and second because Krita 5 saves the brush tips in these presets as well, so the brush tips are integrated in the preset! Krita 4 cannot work with these presets, the “others” should still work.
Michelist