As Zami posted, the revive rates are fixed wherever you are. AFAIK there is currently only one exception:
Bonus Revives for Weaker Defenders - LIVE NOW
Problem: Players permanently losing troops to much higher level players doesn’t feel great.
Solution: Increase the defender revive rate if the attacker’s glory is penalized due to a level differential (only applies if the defender is at a castle owned by their 5TA). If the attacker gets 0% glory, then the defender gets 100% revives. If the attacker gets 100% glory, then the defender gets the current revive rate. Linearly interpolate between these two cases.
Example: Let’s say I’m hitting a lower level player and my glory scaling due to player level is 70%. Let’s say the defender would normally get 60% revives. Instead, the defender will get (60% + (100% - 60%) * (100% - 70%)) = 72% revives. If my glory scaling due to player level was 10% (i.e., I’m way higher level than my target), then the defender in this example would get (60% + (100% - 60%) * (100% - 10%)) = 96% revives.
Edit: Now I’ve actually bothered to read what Zami posted… I never knew there was a reduced revive rate in NML. Is that true ???