There are two issues in law: one is “de jure” and the other is “de facto”.
De jure means that the matter has had a legal conclusion; the Orthodox Churches are de jure in schism.
De facto means that there has not been a legal (as in, Cononical) decision; it means that the facts exist, but no legal decision has been rendered on those facts. A polite what to put it is that the “matter” is “irregular”.
Gerhard Cardinal Muller, while he was head of the CDF, publicly said that the SSPX are not de jure - legally - in schism, but that the are factually in schism.
The net of that is that the Church, starting with Pope Paul VI and continuing through each Pope since then, has made the decision to not press forward with a legal finding that the SSPX are in schism, likely in part due to the fact that it is far easier to reconcile with someone without the legal process providing more bitterness and distance between the parties (as ca be seen with the more than 1,000 years of difficulties between the Orthodox and the Church).
The interview with Bishop Fellay is telling of the difficulties; it is more of the cat-and-mouse statements that have been the constant game of words that have come from the SSPX; in the end he appears to say that the SSPX is still attempting to dictate terms of any reconciliation. Whether that is likely to fly can make for all sorts of cocktail dialogue; but the article is now 22 months old and there does not appear to be any more progress than there was at the time the interview was conducted.
The irregularity is no legal fiction; it is real. It is factual, and at least some significant facts have remained in place since Archbishop Lefebvre and Pope Paul VI got into it.