There was recent discussion on here about where reversals can take place
on the East London Line, for the purposes of stopping the service short.

One of the locations is Shadwell, which is being used this long Easter
weekend to terminate services from points south and (metaphorically)
turn them back round again.

There's a replacement bus service - 'service W' - for all stations to
Dalston Junction, then on to Dalston Kingsland. The main reason for the
closure is Crossrail works at Whitechapel.