if we have gl_sl_link_id null in gl_import_references table what it means ??

we see rows in gl_import_reference with je_header_id, je_batch_id and je_line_id but gl_sl_link_id is null. and respective je_batches are posted in GL but we dont see any connection with SLA module like no entry in xla_ae_header, lines etc.?? does that mean this JE directly created in GL module without SLA ?? if so can we expect its entry in gl_import_references table always ?? Guidance will be highly appreciated