Hi,
[HP5900]display version
HPE Comware Software, Version 7.1.045, Release 2422P01
Copyright (c) 2010-2015 Hewlett Packard Enterprise Development LP
HPE 5900AF-48XG-4QSFP+ Switch uptime is 0 weeks, 0 days, 0 hours, 44 minutes
Last reboot reason : Cold reboot
...
[HP5900]policy-based-route test permit node 5
[HP5900-pbr-test-5]apply ?
next-hop Specify next hops
[HP5900-pbr-test-5]if-match acl name test-acl
[HP5900-pbr-test-5]apply next-hop 192.168.0.1
[HP5900-pbr-test-5]display this
#
policy-based-route test permit node 5
if-match acl name test-acl
apply next-hop 192.168.0.1
#
So, I guess you cannot do "apply default-next-hop", at least not on the R2422P01, software.
Regards