In Shulchan Aruch, Orach Chayim 169:2 the following is noted:
(Source Provided by Sefaria.org)
(לֹא יִתֵּן לֶאֱכֹל אֶלָּא לְמִי שֶׁיּוֹדֵעַ בּוֹ שֶׁיְּבָרֵךְ, הגה: וְיֵשׁ מְקִלִּין אִם נוֹתֵן לְעָנִי בְּתוֹרַת צְדָקָה (הר''י סוֹף פֶּרֶק אֵלּוּ דְּבָרִים
One should only give food to be eaten to someone who knows how to make the blessing (on the food) REMA: There are those who are lenient who say if you give it to a poor person as charity (it is permitted)
It is very popular in a variety of outreach events to provide refreshments and food even in a non-Shabbos meal setting1 (e.g. sushi, cookies, drinks, etc.).
This being said, under these circumstances it is unlikely to assure that those who do not know how to bless make a blessing2.
With the above noted, is there a Heter which Kiruv organizations use when serving food at an event which is likely that the large majority of participants will not recite a blessing on the food they are eating in light of the Shulchan Aruch and Rema quoted3?
1In a Shabbos meal setting, the host would be able to relieve the guests of their obligation with his blessings on wine and bread. Which would not be common in a case of a event where only light refreshments would be served.
2Additionally I have heard (for what its worth) of people involved in Kiruv that making non-practicing Jews make blessings before they eat in a non-ceremonial setting will give the impression that Judaism is too demanding for them, thus causing them to abandon the possibility of becoming a practicing jew.
3 I presume if there is a Heter, it would be based on the Rema but I am unsure how it would work