Would damage the economy no?
Adding anything UL that is primarily used as L today would damage the economy short term. Mining amps, deep finders, mid level weapons, enhancers. They will find their way into the hands of the ones that today buy the most of the L counterparts (as they are the ones willing to pay the most for an UL equivalent)
The long term impact is much harder to anticipate. In the event of say UL damage enhancers, MU would likely drop on finished product, as well as the parts to make them, short term. This might make enhancers more appealing to a wider range of players, which could then bring MU back up a bit. This might fluctuate for a bit until a decently set point is achieved. With enhancer availability being primarily held back by pyrite availabilty (as far as i understand) it is another part to factor in.
In the end, it might damage economy, it may just as well do the opposite. Without proper analysis it is hard to even guess.
On topic:
With a new major event, MA has the ability once again to revamp the structure of item progression without raising eyebrows too much. Perhaps this time they will take this opportunity to breathe some new life into the economy.
I am a firm believer that the best items for any given range of play in any area of the game should be crafted Limited and that UL use should be convenience and filler.
If there are no available L items for you at the moment you use your UL items, with slightly worse expected outcomes.
It would still be fine to have some top end items. A few UL amps, a few high end finders, a few high end weapons. But i think that the influx of items that people want (as described in this, and other threads) is not as desirable as it seems.
Long story short, I would like to see a complete revamp in item structure, however unlikely that would be. A much less unlikely scenario; i hope that MA does what MA thinks is best, and that it turns out well.