AXI modifiable read access

The AXI protocol description states for modifiable transactions (ARCACHE[1] is asserted):

"a read transaction can fetch more data than required"

To me, this can be interpreted in two ways:

1. The RVALID signal of the slave can be asserted for longer than the master has requested through ARLEN
2. An intermediate point can fetch more read data than its master has requested by increasing ARLEN (but RVALID and ARLEN are consistent in each master-slave interaction)

Which of the two is correct?