What a clickbait title of the article. They didn't answer their own title at all. Just said "thousands".
Unlike them, I can answer it based on Slack stats.
6am letter on March 31 was received by around 9591 people.
With overall annual drop indeed over 20k.
1) Slack total for the latest series of mass layoffs which started on Mar24, 2026:
reductions: 16400, additions: 2652
- mar24, 1am UTC: 166542
- mar24, 1:30pm UTC: 166434 (-108)
- mar24, 10:30pm UTC: 166432 (-2)
- mar25, 1pm UTC: 166343 (-89)
- mar25, 3pm UTC: 166325 (-18)
- mar25, 8:30pm UTC: 166092 (-233)
- mar25, 9pm UTC: 166072 (-20)
- mar25, 11pm UTC: 165995 (-77)
- mar26, 1pm UTC: 165865 (-130)
- mar26, 6:30pm UTC: 165800 (-65)
- mar27, 3:30am UTC: 165707 (-93)
- mar27, 2pm UTC: 165736 (+29)
- mar27, 8pm UTC: 165723 (-13)
- mar28, 2:30pm UTC: 165526 (-197)
- mar30, 12:30pm UTC: 165614 (+88)
- mar30, 4pm UTC: 165589 (-25)
- mar30, 9:30pm UTC: 165333 (-256)
- mar31, 2am UTC: 165228 (-105)
- mar31, 5am UTC: 165198 (-30)
- mar31, 12:30pm UTC: 155607 (-9591)
- mar31, 6pm UTC: 155594 (-13)
- mar31, 9:30pm UTC: 155604 (+10)
- apr01, 2:30am UTC: 154796 (-808)
- apr01, 6am UTC: 154682 (-114)
- apr01, 12:30pm UTC: 154756 (+74)
- apr01, 8pm UTC: 154741 (-15)
- apr02, 4:30am UTC: 154576 (-165)
- apr02, 2pm UTC: 154642 (+66)
- apr02, 6pm UTC: 154642 (0)
- apr03, 2pm UTC: 154397 (-245)
- apr03, 11:30pm UTC: 154398 (+1)
- apr04, 11:30pm UTC: 154314 (-84)
- apr06, 1:30am UTC: 154297 (-17)
- apr06, 1:30pm UTC: 154301 (+4)
- apr07, 4am UTC: 154273 (-28)
- apr07, 1:30pm UTC: 154260 (-13)
- apr08, 1pm UTC: 154417 (+157)
- apr08, 11pm UTC: 154441 (+24)
- apr09, 7pm UTC: 154397 (-44)
- apr10, 2pm UTC: 154377 (-20)
- apr11, 2am UTC: 154330 (-47)
- apr12, 2:30am UTC: 154230 (-100)
- apr13, 1pm UTC: 154277 (+47)
- apr13, 10pm UTC: 154275 (-2)
- apr14, 1pm UTC: 155002 (+727)
- apr14, 7pm UTC: 155004 (+2)
- apr15, 2am UTC: 154980 (-24)
- apr15, 2:30pm UTC: 154935 (-45)
- apr15, 10:30pm UTC: 154943 (+8)
- apr16, 1:30pm UTC: 155031 (+88)
- apr16, 9:30pm UTC: 155139 (+108)
- apr17, 3pm UTC: 154888 (-251)
- apr17, 9:30pm UTC: 154914 (+26)
- apr18, 1pm UTC: 154812 (-102)
- apr18, 9pm UTC: 154823 (+11)
- apr19, 2:30pm UTC: 154826 (+3)
- apr19, 11pm UTC: 154832 (+6)
- apr20, 7pm UTC: 154951 (+119)
- apr20, 11pm UTC: 154949 (-2)
- apr21, 1:30pm UTC: 154880 (-69)
- apr21, 10pm UTC: 154890 (+10)
- apr22, 2pm UTC: 154859 (-31)
- apr23, 1am UTC: 154888 (+29)
- apr23, 2pm UTC: 154849 (-39)
- apr24, 1am UTC: 154840 (-9)
- apr24, 7:30pm UTC: 154824 (-16)
- apr26, 1:30am UTC: 154707 (-117)
- apr27, 11:30am UTC: 154780 (+73)
- apr28, 12:00am UTC: 154755 (-25)
- apr28, 2:30pm UTC: 154711 (-44)
- apr28, 10:30pm UTC: 154679 (-32)
- apr29, 4pm UTC: 154239 (-440)
- apr30, 12:00pm UTC: 154192 (-47)
- apr30, 3pm UTC: 154191 (-1)
- may01, 1am UTC: 154093 (-98)
- may01, 12pm UTC: 153788 (-305)
- may01, 9pm UTC: 153865 (+77)
- may02, 2:30pm UTC: 153772 (-93)
- may03, 2pm UTC: 153761 (-11)
- may04, 2am UTC: 153755 (-6)
- may04, 1pm UTC: 153859 (+104)
- may05, 2:30am UTC: 153707 (-152)
- may05, 3:30pm UTC: 153714 (+7)
- may05, 11:30pm UTC: 153684 (-30)
- may06, 5pm UTC: 153660 (-24)
- may07, 1am UTC: 153670 (+10)
- may07, 1pm UTC: 153674 (+4)
- may08, 1pm UTC: 153616 (-58)
- may09, 12am UTC: 153616 (0)
- may10, 3pm UTC: 153439 (-177)
- may11, 1am UTC: 153441 (+2)
- may11, 11:30am UTC: 153566 (+125)
- may12, 4:30am UTC: 153508 (-58)
- may12, 11:30am UTC: 153497 (-11)
- may13, 1:30am UTC: 153455 (-42)
- may13, 12pm UTC: 153625 (+170)
- may14, 6:30pm UTC: 153598 (-27)
- may15, 5:30pm UTC: 153570 (-28)
- may16, 12:30am UTC: 153580 (+10)
- may16, 10:30pm UTC: 153442 (-138)
- may18, 5:30am UTC: 153423 (-19)
- may18, 9pm UTC: 153765 (+342)
- may19, 3pm UTC: 153759 (-6)
- may20, 12am UTC: 153729 (-30)
- may21, 3pm UTC: 153669 (-60)
- may22, 12:30am UTC: 153628 (-41)
- may22, 2:30pm UTC: 153586 (-42)
- may25, 1am UTC: 153460 (-126)
- may25, 2:30pm UTC: 153514 (+54)
- may26, 12pm UTC: 153490 (-24)
- may27, 2pm UTC: 153527 (+37)
- may28, 2:30pm UTC: 153468 (-59)
- may29, 6pm UTC: 153384 (-84)
- jun01, 1pm UTC: 152764 (-620)
2) Annual from Aug to end of May:
reductions: 34577, additions: 11139
- may01-may31: 2241 reductions, and 942 additions
- apr01-apr30: 2286 reductions, and 1583 additions
- mar01-mar31: 12446 reductions, and 844 additions
- feb01-feb28: 943 reductions, and 1143 additions
- jan01-jan31: 1604 reductions, and 1834 additions
- dec01-dec31: 1031 reductions, and 844 additions
- nov01-nov30: 1614 reductions, and 1327 additions
- oct01-oct31: 2504 reductions, 1762 additions
- sep02-sep30: 6275 reductions, 861 additions
- aug14-sep01: 733 reductions (based on Slack very few data points)
- aug01-aug14: ?2900 reductions in IDC (based on media reports)
- jun-jul: no tracking, but no mass layoffs, total was growing in this period