The 1631 Jarosław proclamation1 appears likely to be a fiction developed by the 18th century Christian polemicist Friedrich Christian Meyer, who purported to be a Jewish apostate from Hamburg. Meyer presents this ostensible proclamation from the Va'ad Arba' Aratzos in Hebrew and in Latin translation in his Toledoth Immanuel (1722, pp. 73-74), a cloying missionary screed against Judaism and rabbinic Jews.
I don't have access to manuscripts of any real proclamations made at the Va'ad's autumn assembly at Jarosław in 1631, but I doubt the authenticity of this proclamation on technical grounds:
- The Va'ad would compose its proclamations in Yiddish, not Hebrew.
- The Hebrew proclamation contains multiple linguistic oddities.
- It would be particularly odd to compose this proclamation in Hebrew, as the content of the proclamation regards how to mitigate the effect of hostile Christians who understand Hebrew.
- Meyer indicates that the assembly took place during Elul and Tishrei, but the autumn assemblies in the first half of the 17th century would actually end before Tishrei, presumably due to the holidays (as testified by R' Nathan Hannover in Yeven Metzula, ch. 16, "והיו יושבים בכל יריד לובלין בין בין פורים לפסח, ובכל יריד יערסלב בחודש אב או אלול").
It is possible, if unlikely, that Meyer simply translated the Yiddish proclamation to Hebrew, and failed to mention that he was producing a translation. If so, this would not be the only instance of Jewish self-censorship in the Talmud. In 1508, Gershom Soncino printed a Talmud in Pesaro with substantial lacunae, especially in tractate 'Avoda Zara.2
William Popper (The Censorship of Hebrew Books, 1899. pp. 105-106) notes that censorship of the Talmud in Poland by non-Jewish authorities would be consistent with events at that time, but he uncritically takes for granted the authenticity of the 1631 proclamation calling for self-censorship.3
In any case, I am unaware of any editions of the Talmud that replace text in those relevant parts with mysterious, unexplained symbols. If there was any self-censorship of the Talmud in Europe immediately after 1631, it was not very widespread or did not last very long. The 1644-1648 Benveniste printing of the Talmud in Amsterdam, for example, was uncensored.
1 Some later sources (e.g. here and here) inexplicably place the putative assembly at Petrikau, which is a very unlikely venue for an assembly of the Va'ad Arba' Aratzos in the 1630's.
2 It is noteworthy that the signore and vicariate of Pesaro, Giovanni Sforza, was a former son-in-law of a previous pope. He faced serious political and personal threat from the papacy and the Borgia family, and he was only able to eventually return to Pesaro by the imprimatur of Pope Julius II. Gershom Soncino may have been afraid to risk provoking the papacy, and by extension Sforza, by publishing an uncensored Talmud.
3 Strangely, Popper cites an even more rabidly antisemitic source for this proclamation: Théorie du Judaïsme (1830. pp. 161-165) by Luigi Chiarini.