Seems a last ditch attempt at trying to gain market share at LBA by putting the new Aircraft there. Going on the Grenoble (cancelled already) and Munich routes (approx 50 pax per flight) they have got some serious work to do.
Passengers really don't have any interest in the age of their Aircraft, some of the world better Airlines have large fleets of 20+ year old Aircraft. Passengers decisions are based on three main factors;
A - Price
B - On time departures
C - Convenience of flight departure & arrival times
If they are going to use Aircraft age as a tool to win punters, it's not going to work. Jet2's fleet age is nearly 10 years (on average) older than Monarch, yet Jet2 fill their aircraft to a higher load factor, are roughly similar price wise but get them away considerably more on time than Monarch do. Not to mention they compete in several identical markets and it's clear who is winning at the moment.
Perhaps it will take more than a few leased in 'new' Aircraft and poor marketing to make Monarch a thriving success compared to it's current rather confused and perhaps disillusioned state?