Not sure this is such a massive blow as Pic D’Orhy (their most high profile horse) is long in the tooth now at 11 and outside of the G2 1965 Chase and G1 Ascot Chase (which he was beaten in both this past season having won both the year before) he is exposed at G1 level and I very much doubt he will do much as a 12 year old (probably his last season racing too).
For the last few seasons Nicholls is really missing that marquee horse(s) and I would imagine that No Drama This End (owned by McNeill Family And Chris & Giles Barber) will be the horse he has his hopes set on (as a novice chaser next season and beyond). He is still in the top 4 trainers regularly even though he hasn’t had a big named horse to spearhead his challenge over that period, so I think he is only missing that vital part of the puzzle that when/if found will see him up there challenging more seriously for a title again.
Lets face it, as incredible a season as Skelton had, it will be even harder to replicate it going forward as it is very rare to have most if not all of your yard contributing in such a way again. Last season he had 194 individual winners (from 1026 runners) but just as impressive is the fact that he also had 148 second place horses, 140 3rd place horses and 128 4th placed horses too.
I find it hard to imagine that he can keep that kind of consistency going especially given that you are only one or two injuries to your best horses short of falling from that lofty height.