It’s impossible to say for sure. On one hand, before the Empire took over, many planets beyond the Mid Rim used different currencies and Republic credits were often considered worthless. Even under the Empire, the Wild Space region was not well documented or explored at the time, so Lysatra may have been using a currency of its own.
On the other hand, Imperial credits were known to be much more widely accepted because the economy had stabilized again after the Clone Wars. We know Eli Vanto knew enough about the Empire to choose to become a cadet, so there was at least some contact between the Empire and the worlds in the area. We also know that his parents owned a shipping company, which may have had to use Imperial currency in order to do business closer to the Core, in which case there would have been precedent for standard credits to be introduced in Wild Space.
Overall, I would say sure, if you’d rather have Lysatra using Imperial credits, then why not? My personal guess is that the planet would be in a weird transition phase of accepting both Imperial credits and whatever currency they originally had, supposedly with a conversion ratio of some sort.
Sorry I couldn’t give a solid answer, but I hope that helps a bit!
~ Jacen