Over the years DataWORKS has studied hundreds of textbook adoptions, including the major ones that have recently been adopted for Common Core. Most textbooks on the market today provide English Learner accessible content, not English Language Development content. Accessible content teaches students English Language Arts, and as an aside, they provide shortened stories and simplified questions that are more accessible to English learners. Link to Literacy takes it one step further, helping students build their vocabulary, strengthening their understanding and use of language conventions, and making them more confident in reading comprehension.
That doesn’t mean English learners should not receive grade-level ELA instruction. They absolutely should! But they also need to receive extra support in vocabulary, conventions, and reading comprehension.