I've had a look through the ACL report for winter 2020/2021, compared the slots granted (not just requested) and looked for route changes that have not been already announced. I must emphasise that this is based on slots granted - airlines can and sometimes do decline to take up routes, so this is only a "what might happen", not a "what will happen". In a normal year, many of these routes would have been announced by now; I'm guessing a sizeable number of them simply won't happen:
Air Arabia Maroc:
Fez cancelled
Air Nostrum:
New 2x weekly CRJ1000 to Vigo
Alitalia:
New 7x daily A319 routes to combination of Rome FCO and Milan LIN
China Southern:
New route 5x weekly A330/B787 to Guangzhou
Corendon:
New route 2x weekly B738 to Antalya
Easyjet:
Many new routes or beach routes going from summer-only to year round, but I'm dubious on this. Only 2 additional slot pairs allocated per week compared to previous winter
La Palma cancelled
Enter Air:
New route 1x weekly B738 to Banjul
Iraqi Airways:
Baghdad, Erbil(?) and Sulaimaniyah cancelled
Nouvelair:
New route 2x weekly A320 to Enfiddha
Nordica / Regional Jet:
New route 5x weekly to Tallinn
Ryanair:
New routes (2x weekly extra slot pairs) to Malaga and Sofia
SAS Scandinavian:
New route 3x weekly A320 to Copenhagen
Spice Jet:
New routes 9x weekly 267-seat aircraft to combination of Delhi and Mumbai
Stobart Air:
New route 1x weekly E190 to Belfast City
Swiss:
New route 1x weekly A220 to Sion
Titan:
Lyon replaced by Toulouse
Transavia France:
New route 1x weekly B738 to Paris Orly.
4x weekly slots were requested so this route probably won't happen
TUI:
Mauritius and Pattaya cancelled
Vistara:
New route 1x daily B789 to Delhi
Widerĝe:
New route 6x weekly E190-E2 to Bergen. Widerĝe have also been granted slots for 13x weekly E190-E2 on London City - Bergen
Wizzair:
8 new A321/A321neo slot pairs per day to a combination of:
Alghero, Bratislava, Burgas, Castellón, Constanța, Kaunas, Krakow, Koice, Kutaisi, Lisbon, Lviv, Malta, Ni, Odessa, Olsztyn, Palanga, Poprad, Suceava, Sofia, Satu Mare, Szczecin, Târgu Mureș, Tel Aviv, Varna, Vienna, Warsaw and Yerevan
Most routes are (or recently were) already flown from Luton - but Alghero, Malta, Ni, Odessa and Yerevan look to be new
József Váradi, CEO of Wizz has spoken recently about making Gatwick a major base in London. However only 40% of slots requested were actually granted
Wizzair UK:
13x weekly A321neo to a combination of Larnaca + Suceava
It looks as if Wizz+WizzUK have enough slots at Gatwick for the equivalent of 5 A321s
https://www.acl-uk.org/wp-content/up...rd.-Report.pdf