LTN-MXP is a replacement route of LTN-WAW last flight 5 July.
From MXP to London there are now 16x daily flights:
BA MXP-LHR 4x daily
LH MXP-LHR 6x daily (4x by LHI and 2x by BMI)
U2 MXP-LGW 4x daily
U2 MXP-LTN 2x daily
When you can fly from 99 euro return with Lufthansa MXP-LHR 6x daily or Easyjet MXP-LGW from 60 euro return 4x daily, the new MXP-LTN 2x daily is a no sense flight, also Ryanair has cut BGY-LTN from 2x daily to 4x week. LTN is probably the worst choice for central London.