Broadly speaking, I’d say simulation theory is pretty much more akin to religion than science, since it’s not really testable. We can draw analogies based on what we see in our own works, but ultimately it’s not really evidence based, just ‘hey, it’s funny that things look like simulation artifacts…’

There’s a couple of ways one may consider it distinct from a typical theology:

• Generally theology fixates on a “divine” being or beings as superior entities that we may appeal to or somehow guess what they want of us and be rewarded for guessing correctly. Simulation theory would have the higher order beings likely being less elevated in status.
• One could consider the possibility as shaping our behavior to the extent we come anywhere close to making a lower order universe. Theology doesn’t generally present the possibility that we could serve that role relative to another.