I reckon Ian Lipkin predicted 3-5 years in 2015. Ron Davis I think spoke about 10 years in 2016. Just shows how difficult these kind of predictions are to make. One recurring problem I often see is one cure being hyped (or perhaps hyped is a bit unfair term, as there has been genuine interest and optimism around certain "cures" proposed over the years), but then that hype seems to die down. Here are some on top of my head:
2000s: Various antibiotic courses (stemming mainly from Lyme treatment centers, not of much help in ME/CFS)
2005-: Chia / enterovirus (still some interest, but less than it used to be I reckon)
2005-2010: Staph vaccine (not available anymore)
2007: Lerner / herpesvirus (large dose antiherpesvirals, success turned out to be limited)
2007: LDN (some hype in my country back in that time, but obviously recognized now as not a cure)
2010: XMRV (obviously wrong)
2011: Rituximab (perhaps the most prominent, larger phase 3 study gave a negative result)
2011: Methylation (lots discussed, helped only a few)
2015-: Microbiome / FMT (still some interest, but lacking practical treatments)
2017-: DNRS / LP / brain reprogramming (unfortunately still going)
2018-: Metabolic trap (still to be fully demonstrated, no treatments)
2018: Craniocervical instability (CCI, somehow this died down almost completely in two years after Jen Brea stopped posting in public forums/groups)
2020-: Long COVID (treatments in development, too early to tell what use in ME/CFS)
2020: Abilify (looked very promising at first, effect seems to be lost over time)
2021: Autovaccines (TBD)
...
Might have forgot a few, but the trend is that we discover new hypotheses/treatments that look promising, but over time it doesn't pan out for various reasons and the interest dies down.