Snipping from the CBA available on NHLPA.com
10.1 Unrestricted Free Agents.
(a) Group 3 Players and Free Agents.
(i) Any Player who either has seven (7) Accrued Seasons or is 27 years of age
or older as of June 30 of the end of a League Year, shall, if his most recent
SPC has expired, with such expiry occurring either as of June 30 of such
League Year or June 30 of any prior League Year, become an Unrestricted
Free Agent. Such Player shall be completely free to negotiate and sign an
SPC with any Club, and any Club shall be completely free to negotiate and
sign an SPC with such Player, without penalty or restriction, or being
subject to any Right of First Refusal, Draft Choice Compensation or any
other compensation or equalization obligation of any kind.
Nikishin would be eligible to be an NHL UFA after the 2028-29 season.
After Nikishin's entry level deal ends in 25-26....
July 2026 - Not a free agent (10.2.C status). No Arbitration rights and not offer sheet eligible. A player signing an entry level deal at 22 or 23 has to have 2 years professional experience to get to Group 2 free agency. You need to have played 10 or more Professional games while under contract to accrue a year of professional experience. Assuming Nikishin burns year 1 next week, he will fall short of the 10 games necessary. This will leave him in this 'not a free agent' window where he has no leverage other than not playing.
July 2027 - Group 2 RFA Arbitration rights (offer sheet eligible)
July 2028 - Group 2 RFA Arbitration rights (offer sheet eligible)
July 2029 - UFA
Of course the Canes would most likely try to lock Nikishin into a long term deal well through those Group 2 RFA and early UFA years.