hub concept
the hub concept as it applies to lhr mostly concerns BA . no one else comes close. the following comes from heathrow's schedules of 2nd june 2015 as shown by wikipedia .
87 passenger airlines use lhr. of which 54 go to one destination only (from lhr), 17 go to 2, 5 go to 3, 2 go to 4, 3 go to 5, 2 go to 6, 0 go to 7, 1 goes to 8, 1 goes to 18 (virgin) and BA goes to 143.
figures for cargo : 11 airlines fly to 24 destinations in total.
so there are some hub activities by smaller players but essentially improvements to "maintain lhr's position as a hub" perhaps will disproportionately favour one airline.